Reintegration of crisis services employees: a systematic literature review

Abstract

Purpose

Crisis services personnel are frequently deployed around the globe under highly demanding conditions. This raises the need to better understand the deployment process and more especially, sustainable reintegration after deployment. Despite recent research efforts, the study of the post-deployment stage, more specifically the reintegration process, remains fragmented and limited. To address these limitations, this review aims at (1) describing how reintegration is conceptualised and measured in the existing literature, (2) identifying what dimensions are associated with the reintegration process and (3) identifying what we know about the process of reintegration in terms of timing and phases.

Design/methodology/approach

Following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) protocol, the authors identified 5,859 documents across several scientific databases published between 1995 and 2021. Based on predefined eligibility criteria, 104 documents were yielded.

Findings

Research has primarily focused on descriptive studies of negative individual and interpersonal outcomes after deployment. However, this review indicates that reintegration is dynamic, multi-sector, multidimensional and dual. Each of its phases and dimensions is associated with distinct challenges.

Originality/value

To the authors’ knowledge, this is the first research that investigates reintegration among different crisis services and provides an integrative social-ecological framework that identifies the different dimensions and challenges of this process.

Citation

Glorieux, V., Lo Bue, S. and Euwema, M. (2023), "Reintegration of crisis services employees: a systematic literature review", Journal of Global Mobility, Vol. 11 No. 2, pp. 215-251. https://doi.org/10.1108/JGM-06-2022-0020

1. Introduction

In today's globalised world, international crisis services are increasingly deployed and their engagement has become more relevant (e.g. Blais et al., 2009; Bosustow, 2006; Szkudlarek, 2010; Tanner and Dupont, 2015). Under international crisis services, we understand organisations in which employees may be required to assist in the acute phase of a major incident abroad by providing various types of rescue, emergency and healthcare services (Alexander and Klein, 2009). Examples of such are the military, non-governmental organisations (NGOs) and international police services. During an international deployment, such organisations cover a broad range of organisational and international objectives. Though these objectives can differ between crisis services, the end objective remains the same, that is, aiming at long-term economic, environmental, political and social improvements in the host country, which may be affected by war, poverty, humanitarian, medical or environmental disasters (Alonso and Glennie, 2015). This is shown by the fact that military members can be involved in humanitarian relief, police in military missions, and NGO personnel can be confronted to war situations.

An international deployment is typically described as a cycle subdivided into five stages: pre-deployment, deployment, sustainment, re-deployment and post-deployment (Hall, 2008; Pincus et al., 2001; Thompson and Gignac, 2002). At each stage of their deployment, employees are likely to face challenges that can impact their performance, motivation and well-being (Hall, 2008; Pincus et al., 2001). Therefore, it is crucial that each stage and its impact are thoroughly studied and documented (Brookfield, 2015; Szkudlarek, 2010; Tanner and Dupont, 2015). While the challenges experienced at the pre-deployment or deployment stage and the means available to manage them are well understood (Baptist et al., 2011; Hall, 2008; Pincus et al., 2001), the post-deployment stage has been neglected both in the literature and in organisational policies (Kraimer et al., 2012; Szkudlarek, 2010).

Post-deployment, starts when the employee returns home upon completion of the mission. This stage includes finding their place back again as an individual in their families, their regular jobs and their social life (Blais et al., 2009). This process of re-adapting to life in the homeland is called “Reintegration” (Blais et al., 2009; Elnitsky et al., 2017a, b). Reintegration itself can be considered as a multidimensional dynamic process that can be placed in Bronfenbrenner's models (1979, 2005). His bioecological model (2005) identifies five interrelated systems that can influence the growth and development of an individual: the microsystem (immediate environments), mesosystem (connections between environments), exosystem (indirect environments), macrosystem (social and cultural aspects) and chronosystem (time-related aspects). In his previous model – the social-ecological framework – Bronfenbrenner (1979) viewed the individual as an entity that interacts in and with his/her immediate environment and who is impacted by four types of dimensions: individual, interpersonal, professional and societal (Blais et al., 2009; Bronfenbrenner, 1979; Elnitsky et al., 2017a, b; Lubens and Bruckner, 2018; Reistetter and Abreu, 2005; Resnik et al., 2009).

In this review, we decided to focus on the individual and his/her immediate environment – hence on his/her microsystem and its dimensions – for several reasons. First, we aim to focus on the reintegration experiences of the individual who is returning and not of the environment or the interactions between environments. Second, such an approach is in line with past research endeavours that also identified these dimensions (Blais et al., 2009; Elnitsky et al., 2017a, b; Lubens and Bruckner, 2018; Reistetter and Abreu, 2005; Resnik et al., 2009). Using these dimensions responds to the call of integrating reintegration research instead of creating more fragmentation. Third, we did not include the societal dimension, macrosystem and exosystem, since Blais and colleagues (2009) imply that the psychological influences of these are indirectly reflected and perceived in the other dimensions of the reintegration process. This finding is also reflected in the research of Vélez-Agosto and colleagues (2017) who state that social and cultural aspects should be moved from the macrosystem to the microsystem. Thus based on Bronfenbrenner's works (1979, 2005), we define reintegration as a process of resuming roles in several dimensions of the microsystem (Figure 1): one's own life (individual reintegration), social network (interpersonal reintegration) and workplace (professional reintegration), which may be influenced by different levels of the social-ecological system (Elnitsky et al., 2017a).

Research on the reintegration of crisis services employees is still limited, for at least two reasons. First, reintegration research has primarily focused on mapping the repatriation of expatriates working for private companies (Baruch et al., 2016; Breitenmoser and Bader, 2016; Caligiuri and Bonache, 2016; Greer and Stiles, 2016; Kraimer et al., 2016; Szkudlarek, 2010), overlooking the empirical and practical issues associated with the reintegration of crisis services personnel. Crisis service employees differ from these expatriates because the firsts operate in fast-paced, hazardous, acute and hyperdynamic environments (Boermans et al., 2014). The fact that those services personnel work during crises puts more adaptation demands on them during the deployment and thus more adaptation demands when they return home. In addition, during deployment, crisis service members are more prone to losing resources that enable their physical and psychological well-being and this process of loss can continue during the post-deployment stage (Vinokur et al., 2011). Nevertheless, we acknowledge that recent research (Faeth and Kittler, 2020) has shown that expatriates can also work in a hostile environment, in which they are exposed to higher demands. Although this remains exceptional, what we will learn from the present review may be generalisable to these cases.

Second, a common belief in the repatriation literature and among several researchers is that the challenges encountered after deployment are less severe than during deployment (Black, 1992; Chiang et al., 2018; Knocke and Schuster, 2017). This can explain why the issue of reintegration received less attention in the literature (Kraimer et al., 2012; Szkudlarek, 2010) and why organisations put less effort into correctly and sufficiently drafting post-deployment policies, even though they have a legal and moral duty to care for their personnel well-being.

Research on crisis services employees' reintegration is also fragmented along four lines. First, the available literature has mainly focused on military personnel, giving limited insights into the reintegration process of non-governmental personnel and police officers (Chiang et al., 2018; Drodge and Roy-Cyr, 2003; Knocke and Schuster, 2017; Szkudlarek, 2010; Tanner and Dupont, 2015). Nevertheless, the military literature may provide useful insights to understand the other crisis services personnel reintegration processes and challenges, since they face similar issues during the deployment, such as harsh working or living conditions, long periods of time spent abroad and complex cross-cultural hurdles (Alexander and Klein, 2009; Boermans et al., 2014; Drodge and Roy-Cyr, 2003).

Second, many studies tend to focus on one dimension (individual, interpersonal, professional) at a time and fail to provide a holistic view that captures the reintegration process across multiple dimensions concurrently (Blais et al., 2009; Elnitsky et al., 2017a; Lubens and Bruckner, 2018).

Third, the existing literature tends to focus on the negative aspects of reintegration. Depression, anxiety, substance abuse or post-traumatic stress (e.g. Blais et al., 2009; McCreary et al., 2014; Newby et al., 2005) are often the studied outcomes despite emerging evidence that returning personnel may also experience positive outcomes such as increased well-being, self-esteem, or a renewed sense of purpose (Blais et al., 2009; Fikretoglu and McCreary, 2010; McCreary et al., 2014).

Fourth, researchers often describe reintegration as a static event or an outcome that can be good or bad (Bolton et al., 2002; Mankowski et al., 2015; Maruna et al., 2004). However, the social-ecological framework indicates that reintegration needs to be considered as a dynamic process where a returning employee interacts with the environment (Bronfenbrenner, 1979; Elnitsky et al., 2017a, b; Lubens and Bruckner, 2018). This shortcoming hinders research to investigate reintegration as a process that evolves over time with phases entailing distinct challenges.

Our review contributes to the literature on the subject in several ways. First, it is the first of its kind to systematically identify and report on literature concerning reintegration across different sectors of crisis services. Although research on the reintegration of non-governmental personnel is limited, we provide a general reintegration perspective of crisis service employees with the necessary nuances across the different sectors. In addition, we use the military literature to provide essential insights on reintegration of non-governmental personnel. Second, we try to respond to the current fragmentations by structuring our line of thoughts by using Bronfenbrenner's social-ecological framework. This enables us to explore reintegration across several dimensions (individual, interpersonal, professional) and two kind of outcomes (positive and negative). Therefore, our review sheds the light on different dimensions, on specific challenges and on how these challenges enhance or hinder the individual's reintegration process and outcomes. Third, while researchers often consider reintegration as a static event, this review shows that reintegration is a dynamic process. In sum, this systematic literature review aims to move away from a fragmented, mono-domain, static and problem-focused perspective to identify the different elements of this multi-sectorial, multidimensional, dual and dynamic construct “Reintegration”.

We structured the review as follow. In the next section, we outline the search strategy to systematically collect and synthesise relevant literature. After rigorously categorising, coding and labelling the relevant findings, we present them according the reintegration dimension or process of the social-ecological framework. We address three research questions: (1) How is the reintegration process conceptualised and measured in the existing literature? (2) What dimensions are associated with the reintegration process? 3. What do we know about the process of reintegration in terms of timing and phases? The paper concludes with a discussion where we consider the key contributions, practical and theoretical implications and limitations.

2. Method

We followed a four-step procedure to carry out our systematic review (Higgins2019; Keathley et al., 2016; Tranfield et al., 2003). First, we identified the problem and a study scope with an initial scoping search. Second, we determined a search strategy in an iterative protocol based on the PRISMA statement (Moher et al., 2009). We pre-registered this protocol on the Open Science Framework (osf.io/j8grc and DOI: 10.17605/OSF.IO/4DHNB). Third, we extensively searched three different databases and assessed the quality and relevance of the found documents based on predefined eligibility criteria. Fourth, we analysed the final set to formulate an answer to our research questions.

2.1 Search strategy

To obtain documents relevant to our research questions, we selected a broad set of different search terms that reflected the theme of reintegration across different crisis sectors. These terms were derived from the initial scoping search, were reviewed by the different authors and tested for relevant hits. With these search terms, we developed a Boolean phrase for each sector. It coupled all the synonyms of “reintegration” with the Boolean operator OR with all the synonyms of the sector with the Boolean operator AND. The Boolean phrases are available on request. Through iterative pilot testing, we refined our Boolean phrases over time with different searches and combinations (Aveyard, 2018; Randolph, 2009; Wanyama et al., 2022). The entire search process and necessary refinements were recorded. This to answer to the scientific need to clarify and communicate our retrieval strategy in a clear protocol even when refinements or amendments took place (Page et al., 2021; Randolph, 2009; Wanyama et al., 2022).

We chose to perform our search with two well-established online databases: Web of Science, Scopus and one well-established online register Google Scholar. We based our decision for these three databases on an informed assessment of the scientific literature and the different databases to adequately formulate an answer to the scope of our study and to reduce search engine bias (Keathley et al., 2016; Saunders et al., 2018; Wanyama et al., 2022; Webster and Watson, 2002). Scopus and Web of Science are well-suited to synthesise evidence (Gusenbauer and Haddaway, 2020) and Google Scholar is more used for supplemental information and grey literature gathering (Gray et al., 2012). Furthermore, we complemented and enhanced our database searches with backward snowballing where we reviewed the references in each documents to identify additional relevant studies (Wanyama et al., 2022; Webster and Watson, 2002).

The following study characteristics were included to select documents for analysis: (1) All studies that focused on reintegration, even if they merely focused on one phase or dimension of the process; (2) Studies with a focus on military personnel, police forces or non-governmental personnel who were sent abroad; (3) Studies that help to answer at least one of our research questions; (4) Studies in which the reintegration process is part of the research question or a variable; (5) Studies (re)conceptualising the reintegration process; (6) Empirical studies with a quantitative, qualitative, or mixed design. Regarding the reporting characteristics, the search was restricted to English language articles published in peer-reviewed academic journals between 1995 and 2021. For the sake of completeness, we also included grey literature such as instructional guides, book chapters and reports.

Besides, the following studies were excluded: (1) all studies that did not mention reintegration in the research question or the whole document; (2) all studies with a focus on physical injuries, neurological conditions, or mental illness which may affect the reintegration process; (3) studies with a population or sample out of our scope (not a crisis service member); (4) employees who are sent less than three months abroad; (5) Reintegration is only mentioned in the title or references without elaboration in the document itself. We also excluded documents without reference list; quantitative studies with a sample smaller than 30 participants; and quantitative studies with a sample smaller than six participants. Throughout the study selection, we added two exclusions criteria based on the principle of iterative search process (Page et al., 2021; Randolph, 2009; Wanyama et al., 2022): (1) all studies that focus more on the whole deployment cycle than on the post-deployment phase and (2) studies with a focus on post-deployment interventions.

2.2 Study selection

The first author conducted a comprehensive systematic literature search between 10/05/2021 and 12/05/2021. Additionally, the Boolean phrases were registered into the different online databases to alert us when new relevant documents were published. We identified 8,561 titles initially (see Figure 2 for the PRISMA flow diagram). Ten documents were identified by using a backward snowballing technique (Webster and Watson, 2002). Duplicate references were removed (n = 2,712), and the remaining abstracts (n = 5,859) were independently reviewed on the eligibility criteria by the first author. A second independent reviewer reviewed 20% of the 5,859 abstracts for control. Then, the author evaluated the remaining 656 documents and the independent reviewer 20%, by examining the full text. Documents that did not meet one of the inclusion criteria were excluded. When in doubt, the reference was retained until the next step. The interrater reliability Kappa of the abstract screening was 0.62 and 0.63 for the full-text screening. Based on the research of Cohen (1960), we can interpret this as substantial interrater reliability. In the end, we included 104 documents.

2.3 Data synthesis

The final dataset (n = 104) included a wide range of different study designs, samples, focus points and outcomes. Because of this heterogeneity, we provide a qualitative synthesis of the documents included using a qualitative data analysis software (Nvivo 11). We categorised, coded and labelled the relevant findings based on the social-ecological framework (Bronfenbrenner, 1979; Elnitsky et al., 2017a; Lubens and Bruckner, 2018). It allowed us to systematically categorise and analyse the documents following the reintegration dimension (individual, interpersonal or professional), process, or phases they focused on. In the results section, we will first describe the study characteristics, the used definitions of reintegration and the measurement tools. Further in the text, we will focus on the different reintegration dimensions and their specific challenges. Finally, we will discuss the reintegration process and its timeframe.

3. Results

The studies varied widely in terms of design, sample and dimension of reintegration they focused on, but we still observed a few trends. Our study sample consisted of 91 published peer-reviewed articles, six scientific reports, four chapters, two books and one doctoral thesis. Of the 104 included studies, the majority focused on military reintegration (n = 86), only a few studies focused on NGOs (n = 13) and the police (n = 5). Noteworthy is that the interpersonal dimension (n = 42) was studied primarily, followed by the individual dimension (n = 35). In 21 studies, all dimensions – individual, interpersonal and professional – were addressed simultaneously. For the study designs, a quantitative approach (n = 39) was used mostly, followed closely by a qualitative one (n = 32). However, a significant proportion of the documents (n = 26) addressed reintegration at a mere theoretical level. Only a few studies used a mixed-method design (n = 7). Sample sizes ranged from 6 participants (Hearns and Deeny, 2007) to 22.150 participants (Welsh et al., 2015). The research has a peak around the years 2014–2016 with 35 published studies. Even though our initial time period search was between 1995 and 2021, the oldest document included through the inclusion criteria was published in 2001.

3.1 How is the reintegration process conceptualised and measured?

Reintegration has been previously named community reintegration, homecoming, (combat-to-home) transition, a new biopsychosocial spiritual homeostasis state, or readjustment. These definitions can be considered as an event (e.g. homecoming), outcome (e.g. homeostasis), or process (e.g. readjustment) (Elnitsky et al., 2017a, b; Maruna et al., 2004). Homecoming is the reception during which returning employees are welcomed back by their social networks (Bolton et al., 2002; Heinecken and Wilén, 2019). Transition is characterised by a disruption in current routines and roles because they are insufficient to navigate returning home (Adler et al., 2011a, b; Knobloch and Theiss, 2018). Reintegration conceived as an “outcome” can be defined as the set of positive and negative consequences of the deployment after the return. These outcomes can impact the functioning of the individual in his/her social network, the organisation, or the society (Hoge et al., 2006). Lastly, research has attempted to define reintegration as a process (e.g. community reintegration, readjustment). Community reintegration happens when employees transition from deployment to home life (Cogan, 2016; McColl et al., 2001; Resnik et al., 2009; Willer et al., 1994). Readjustment consists of two elements: adjusting to social life and adjusting to their career (Katz et al., 2007, 2010). However, these definitions fail to include all dimensions of reintegration: individual, interpersonal and professional, even though these three dimensions are recognised by many researchers (e.g. Beder et al., 2011; Currie et al., 2011; Denning et al., 2014; Elnitsky et al., 2017a, b; Fikretoglu and McCreary, 2010; Lubens and Bruckner, 2018; McCreary et al., 2014; Milliken et al., 2007; Padden and Agazio, 2013; Rivers et al., 2017; Sorsdahl, 2010; Wooten, 2013).

Between 2001 and 2021, twelve questionnaires have been developed to measure reintegration (Table A1, Appendix 1). Overall, several instruments measure reintegration as a negative phenomenon or focus on one of the three dimensions. Some instruments do consider the multidimensional (individual, interpersonal and professional) and dual (positive and negative) aspects of reintegration (Adler et al., 2011a, b; Blais et al., 2003, 2006). All these measurements also reflect the various terms used to describe reintegration: (combat-to-home) transition, community reintegration and readjustment (Adler et al., 2011a, b; Blais et al., 2009; Fink et al., 2014; Katz et al., 2007, 2010; McColl et al., 2001; Resnik et al., 2009).

As reported in Table A2 (Appendix, 2), the selected studies have used or mentioned several models in their attempts to explain reintegration. We note that most reintegration models are linked to interpersonal (family) or individual theories focusing on negative outcomes. In sum, the conceptual and terminological proliferation around the construct of reintegration results in a lack of a universal model to describe and study it. In this review, we consider reintegration as a multidimensional dynamic process that can be placed in Bronfenbrenner's social-ecological framework (1979, 2005).

3.2 What dimensions are associated with the reintegration process?

As earlier described, an employee needs to reintegrate on the individual, interpersonal and professional dimensions of the social-ecological framework. The influence of the societal dimension is indirectly reflected in the other three dimensions (Blais et al., 2009; Vélez-Agosto et al., 2017). Based on our analysis, we can make two observations.

First, on the one hand, difficulties in reintegration relates to the individual, interpersonal and professional challenges that employees keep experiencing even after the reintegration process is complete (Knobloch et al., 2013, 2019). On the other hand, positive reintegration involves successful adaptation and growth to changes and challenges at the individual, interpersonal and professional dimensions (Cunningham et al., 2014; Denning et al., 2014). Second, employees can encounter paradoxical reintegration experiences (Castro et al., 2015): they are happy to be home, but at the same time have difficulty to relax, to be vulnerable and to let go of the deployment experiences. This phenomenon indicates that both positive and negative outcomes can occur at the same time and suggests a possible dual-process of reintegration. In the next subsections, we will examine the effect of each dimension of the social-ecological framework and their specific reintegration outcomes.

3.2.1 Individual reintegration

Individual reintegration refers to how employees readjust after deployment and meaningful integrate their experiences into their personal lives (Clark et al., 2018; Cunningham et al., 2014; Knobloch and Theiss, 2012; Mankowski et al., 2015). In the next subsections, we will discuss individual capabilities that can help the individual to reintegrate. Thereafter, we will examine the different reintegration experiences on the four sublevels of individual reintegration: emotional, physical, spiritual and behavioural. These individual experiences can increase or decrease the likelihood of successful reintegration and their quality of life (Denning et al., 2014; McCormack and Joseph, 2012; Paton, 2006; Wesemann et al., 2018).

3.2.1.1 Individual capabilities

Individual capabilities addressed in reintegration research include identity, resilience and coping. Capability is the ability to undertake actions or adapt to changes (Oxford Dictionaries) and go beyond personality traits. They entail the interaction between an individual, his/her experiences and the current situation (Eisen et al., 2014). Hence, they can determine and affect the reintegration process outcomes (Lindbom et al., 2015). For example, these capabilities enable an employee to fully understand and reflect on the deployment experiences, its implications and the post-deployment changes (Blais et al., 2009). Accordingly, vulnerability is the lack of this ability. Below is a point-by-point overview of the individual capabilities of identity, resilience and coping.

After deployment, employees can experience identity disruption which is a set of discontinuities in the identity that arise in response to major life changes (Balderrama-Durbin et al., 2015; Cogan, 2016; Danish and Antonides, 2013; Elliott, 2015; Fahim et al., 2014; Knobloch et al., 2016; Mitchell et al., 2020; Newby et al., 2005; Rivers et al., 2013; Rubin et al., 2016; Scannell-Desch and Doherty, 2015; Yablonsky et al., 2016). A solution is to integrate these events into their identity by taking what they have learned and applying it to their life (Campbell and Warner, 2016; Mitchell et al., 2020; Tobin, 2015). This is also called “identity integration” and can be perceived as a capability. Research indicates that employees who are able to integrate their challenges and experiences into their identity and life have higher well-being (Lilgendahl, 2015).

Resilience is a transactional process that influences the capability to maintain healthy psychological and physical functioning while being exposed to highly stressful events (Eisen et al., 2014; Elliott, 2015; Weseman et al., 2018; Wooten, 2013). Two antecedents of resilience are self-efficacy and hardiness (Brooks et al., 2015; Comoretto et al., 2015; Eisen et al., 2014). The former represents the belief that an individual can cope with stressful events and solve them (Eisen et al., 2014). The latter includes the belief that experiences are controllable, have meaning and are an opportunity to grow (Eisen et al., 2014). A specific outcome of resilience is post-traumatic growth which means that employees feel that they personally and professionally benefit from the hardship they have endured and go hand in hand with personal accomplishment, improved self-confidence, increased compassion, recognition of new possibilities, re-evaluation of the self and priorities (Beder et al., 2011; Brooks et al., 2015; Cunningham et al., 2014; Eisen et al., 2014; Tobin, 2015; Wesemann et al., 2018; Wooten, 2013; Wright et al., 2015).

In our review, eight studies examined the impact of different maladaptive (vulnerability) and adaptive (capability) coping strategies on reintegration (Brooks et al., 2015; Chandler et al., 2018; Comoretto et al., 2015; Eisen et al., 2014; Mattocks et al., 2012; Taff et al., 2016; Thompson and Gignac, 2001; Thompson and Pastò, 2003). Overall, if employees had negative expectations about the reintegration process, they are more likely to use maladaptive coping strategies (Thompson and Gignac, 2001). Maladaptive coping strategies will enable avoidance behaviours that block off emotions by binging and purging, compulsive spending, over-exercising and abusing drugs (Mattocks et al., 2012; Thompson and Pastò, 2003). On the contrary, adaptive coping strategies can enhance positive reintegration experiences by using different strategies that can be categorised as problem-focused (planning and taking action), emotion-focused (diminishing emotional distress), cognitive-focused (appraisal), behavioural-focused (leisure) and relationship-focused (seeking social support) (Chandler et al., 2018; Dattilo, 2015; Mattocks et al., 2012; Miller and Warner, 2013; Taff et al., 2016; Thompson and Pastò, 2003; Wright et al., 2015).

3.2.1.2 Individual experiences

The individual capabilities interact with a number of different experiences on the emotional, physical, spiritual and behavioural levels of individual reintegration. Crisis services personnel are at risk of developing negative reintegration experiences in different key life domains. Nevertheless, positive experiences can favourably influence the reintegration process (Blais et al., 2009; Newby et al., 2005). Table 1 presents an overview of the individual reintegration experiences. Although some examples are derived from military experiences or are typically depicted in the military literature, we can observe that all crisis service employees from different organisational background, whether they are military service members, non-governmental personnel, or police officers, might experience individual feelings such as, emotional disconnection and adrenaline-seeking behaviours. This will be further elaborated in the following paragraphs.

The first kind of experience is emotional reintegration. In our review, 22 studies mention that returning employees are at risk for a wide range of emotional difficulties that influence the reintegration process such as anxiety, existential distress and conflicting emotions. A characteristic of anxiety is uncertainty about the future and is accompanied by existential distress that occurs when employees grapple with finding new meaning throughout life changes (Cornish et al., 2014; Elliott, 2015; Knobloch et al., 2013; Rivers et al., 2017). For conflicting emotions, we differentiate between, on the one hand, isolation and helplessness, which all crisis service employees may experience and on the other hand, hostility and disconnection, which are more typical examples for military service members. Isolation and helplessness may come from the feeling of no longer contributing to a goal or returning to a social circle made of people who did not share the experiences of deployment. These feelings are a strong predictor of PTSD up to 10 years after the return (Thompson and Gignac, 2001). Hostility and disconnection can be intensified by employees who still use emotional deployment strategies such as emotional constriction, numbing and detachment in the post-deployment stage which in turn intensifies aggressive or reckless behaviour (Bowling and Sherman, 2008; Brenner et al., 2015; Danish and Antonides, 2013; Lusk et al., 2015). Even though the literature on these emotional outcomes is limited, deployment can have several positive emotional consequences. In general, employees mention strengthened relationships, increased self-esteem, broadened life perspective, perception of personal growth and improved life priorities. These positive consequences are mainly associated with the way the employee appraises the deployment, or put another way, if an employee is able to recount the positive effects of their deployment (Thompson and Pastò, 2003).

The second kind of experience is related to physical reintegration. When employees return home, they face environmental and physical changes that can affect reintegration. First, employees may experience increased sensitivity to stressful triggers (images, sounds and smells), activating hypervigilance and hyperactivity (Baptist et al., 2011; Cornish et al., 2014; Scannell-Desch and Doherty, 2015). During the deployment, this was protective to anticipate and be able to immediately react to potential urgent situations and risks (e.g.: crowd control, terrorist attack, medical situations, kidnapping); however, during the post-deployment stage, it can alter the quality of life by increasing irritability, aggression, anxiety and sleeping problems (Baptist et al., 2011; Drodge and Roy-Cyr, 2003; Elliott, 2015; Heinecken and Wilén, 2019; Laser and Stephens, 2011; Mattocks et al., 2012; Padden and Agazio, 2013; Scannell-Desch and Doherty, 2015; Wooten, 2013). Second, the strict structure of deployment for example, the demand of being available the majority of day and long working hours, seems to disappear and employees need to adjust to changed daily living arrangements which can impact eating, sleeping and exercising habits. For example, employees can experience physically exhaustion (Bowling and Sherman, 2008; Fahim et al., 2014) or compassion fatigue (Makinen et al., 2015), that is, the fatigue of helping others. However, physical exercise in the form of leisure can have beneficial effects on the reintegration process by improving their well-being, re-finding their identity, diverting their attention, relieving stress (Chandler et al., 2018; Dattilo, 2015; Miller and Warner, 2013; Taff et al., 2016).

The third kind of experience is behavioural reintegration. On the negative side, difficulties include substance misuse, aggression, dealing with stigma, suicide attempts and adrenaline-seeking behaviours. As earlier mentioned, aggression and adrenaline-seeking behaviours are more typical military examples. Adrenaline-seeking behaviours involve reckless, unlawful, danger-seeking and sometimes antisocial behaviours that try to recreate and cope with the intensity of deployment (Blais et al., 2009; Bowling and Sherman, 2008; Elnitsky et al., 2017b; McCreary et al., 2014). These can be enhanced by the feeling that various deployment skills – like handling critical life threatening situations– are unnecessary when they return (Cogan, 2016). The perception of stigma, that is, the idea that something negative will happen when they seek help, can influence the help-seeking behaviour of an employee (Fahim et al., 2014; Finnegan et al., 2016; Lusk et al., 2015) and potential career possibilities (Cornish et al., 2014). Positive behavioural experiences are, for example increased leadership ability, new strengths and skills, a sense of contributing to a greater good, more effective communication and new friendships (Baptist et al., 2011; Knobloch et al., 2016; Newby et al., 2005).

The fourth kind of experience is spiritual reintegration. During reintegration, employees can struggle with making sense of what happened during deployment. They can question their religious beliefs and experience guilt and conflicting values (Danish and Antonides, 2013). Nevertheless, spiritual practices and faith can provide strength, stimulate coping, facilitate a better understanding and offer emotional support (Baptist et al., 2011; Mankowski et al., 2015; Miller and Warner, 2013; Wooten, 2013).

To conclude, individual reintegration includes individual capabilities and reintegration experiences on the emotional, physical, behavioural and spiritual levels. First, we identified three individual capabilities: identity, resilience and coping. Second, even though we limited our research to studies that did not focus on injuries, neurological conditions, or mental illnesses, there was still a predominant focus on negative individual experiences, which largely outweigh the positive reintegration experiences. Third, as earlier indicated, all crisis service employees, whether they are military service members, non-governmental personnel or police officers, might experience individual feelings who are typically depicted in the military literature. So those experiences might also occur to other professionals deployed abroad for a long high-intensity crisis deployment.

3.2.2 Interpersonal reintegration

Interpersonal reintegration entails changes and adjustments in how individuals (re)define their relationships, roles and responsibilities (e.g. Elnitsky et al., 2017a, b; Gil-Rivas et al., 2017; Hollingsworth et al., 2016; Knobloch and Theiss, 2011; Thompson and Gignac, 2001). For example, when returning home, the employee must adapt from deployment life to home life, and the partner must adjust from independence to interdependence (Knobloch-Fedders et al., 2020). This can feel like switching a coin, because an employee transitions from an environment where he/she had some responsibilities, to a home where a partner has been fully in charge (Baptist et al., 2011; Hollingsworth et al., 2016; Laser and Stephens, 2011; Padden and Agazio, 2013; Pincus et al., 2001; Yablonsky et al., 2016). This switch entails renegotiating roles, which consists of redistributing control and adapting to new responsibilities (Banwell et al., 2016; Cogan, 2016; DeVoe et al., 2020; Drodge and Roy-Cyr, 2003; Knobloch et al., 2016; Knobloch and Theiss, 2011, 2012; Melvin et al., 2015). In the next subsections, we will discuss to which prominent roles (partner, children and friends) individuals return to and how they go through the role renegotiation process. Due to the hypothesised dual reintegration process, we will examine both sides, positive and negative, of each interpersonal challenge.

3.2.2.1 Interpersonal roles

In this review, single employees are defined as individuals who are divorced, separated, or never married (Bray et al., 2011; Riviere and Merrill, 2011). Several studies suggest that being single can influence the interpersonal reintegration experience in different directions. First, research of Newby and colleagues (2005) states that single employees experience more positive consequences of deployment than married employees such as making additional money, self-improvement and travelling to another culture. Second, other studies observed that single employees are more prone to developing physical or emotional health problems, unhealthy coping strategies, risky behaviours and substance abuse than their married colleagues (Bray et al., 2011; McCreary et al., 2014; Riviere and Merrill, 2011). However, experiencing partner loss can also increase distress (Bray et al., 2011; Riviere and Merrill, 2011).

During the post-deployment stage, parent-child relationships often need to adjust to each other's renewed presence. Returning parents fear that their children will not trust them, no longer need them, or not respect their authority (Curry et al., 2018; DeVoe et al., 2020). Children, on the other hand, may be afraid to get close again, need to adapt to the renewed presence of two parents and to overall changed family dynamics (Balderrama-Durbin et al., 2015; Bowling and Sherman, 2008; Knobloch et al., 2016; Pincus et al., 2001; Yablonsky et al., 2016). While re-establishing a connection with children, employees can experience a sense of alienation from routines, reluctance to set limits and uncertainty about what to do and how to handle children's emotions (Curry et al., 2018; DeVoe et al., 2020; Mattocks et al., 2012). Deployed parents also need to cope with guilt, anger and resentment for not having been there for a certain period (Elliott, 2015; Curry et al., 2018; Heinecken and Wilén, 2019; Miller and Warner, 2013; Newby et al., 2005; Walsh, 2017).

During deployment, employees had often minimal contact with their friends at home, and now they need to reconnect again (Melvin et al., 2015). This leads to several challenges that can trigger feelings of alienation and loneliness (McCormack and Joseph, 2012; Thompson and Gignac, 2001). First, employees describe difficulty reuniting and interacting with friends who are involved in another type of work due to the delicate balance of interest (Lusk et al., 2015; Sherman et al., 2015). On the one hand, friends that show no interest make the individual feel that his/her experiences are not valid (Albuquerque et al., 2018; Cornish et al., 2014; McCormack and Joseph, 2012; Rivers et al., 2013, 2017; Sorsdahl, 2010). On the other hand, being too interested can also be challenging due to constantly recounting stories (Rubin et al., 2016). Employees can experience the so-called “silence paradox” where they want to be understood, but do not want to talk about the deployment (Castro et al., 2015; Sherman et al., 2015). Second, the possible nature of the deployment can bring individuals to fear others' reactions and therefore sometimes change their behaviour and stories (Feldman and Hanlon, 2012; Mattocks et al., 2012; Rubin et al., 2016; Sherman et al., 2015; Sorsdahl, 2010). Third, research suggests that employees can experience difficulties relating to their friends and can manifest a low tolerance for complaints (Brenner et al., 2015; Cornish et al., 2014; Elliott, 2015; Lusk et al., 2015; Scannell-Desch and Doherty, 2015).

Hence, interpersonal relationships and their respective roles can challenge or facilitate the reintegration process, life satisfaction and well-being. The outcomes depend on how individuals act and engage with each other, communicate, handle and solve conflicts and establish a new reality (Bowling and Sherman, 2008; Denning et al., 2014; Knobloch et al., 2016; O'Neal et al., 2018; Wooten, 2013). More precisely, how individuals renegotiate interpersonal roles through communication, connection, support and coping.

3.2.2.2 Interpersonal role negotiation

Role renegotiation starts with homecoming. However, as earlier mentioned, homecoming is not always a happy event due to the actual reintegration process that can include uncertainties and changes concerning their interpersonal relationships and roles (Beder et al., 2011; Elliott, 2015; Finnegan et al., 2016; Padden and Agazio, 2013). These uncertainties and changes can be addressed and resolved by renegotiating roles in interpersonal relationships (with partner, children and friends). In general, role renegotiation requires time, patience and efforts and can be perceived as a turbulent process (Knobloch et al., 2016; Knobloch and Theiss, 2012; Laser and Stephens, 2011; Pincus et al., 2001). Especially, when families want to give responsibilities and roles back to an unready employee (Baptist et al., 2011; Bowling and Sherman, 2008; Elliott, 2015; Hollingsworth et al., 2016; Knobloch and Theiss, 2012; Lusk et al., 2015; Scannell-Desch and Doherty, 2015).

Role renegotiation contains different processes that can facilitate or hinder reintegration. First role flexibility, role clarity and role maintenance can ease role renegotiation and thus reintegration (Bowling and Sherman, 2008; Hollingsworth et al., 2016; Knobloch and Theiss, 2011). Role flexibility entails families adapting to new circumstances, and offering needed adjustment time (Hollingsworth et al., 2016). Role maintenance entails strategic and routine behaviours that uphold, sustain, or improve the role renegotiation and positively influence the reintegration (Bowling and Sherman, 2008; Knobloch and Theiss, 2014). Role clarity assumes that every member understands the expectations tied with the role (Balderrama-Durbin et al., 2015). Two processes can hinder the reintegration process: role ambiguity and role conflict. When there is no understanding, role ambiguity (“Who does what now?”) occurs and can impact the reintegration process (Yablonsky et al., 2016). Role conflict occurs when individuals struggle with completing their various roles, such as a conflict between being a crisis service employee and being a partner (Walsh, 2017). It can also occur when individuals interfere role renegotiation by disrupting routines, making it harder to establish new routines (Baptist et al., 2011; Knobloch and Theiss, 2011). There are three conditions that can positively influence the role renegotiation process: communication, connection and coping. In the next subsections, these will be discussed one by one.

The first condition is communication. Couples need to be aware that they have to change their communication pattern compared to during the deployment (McAdams et al., 2018). Specifically, an employee needs to change his/her professional style, adapted for the deployment, to a more familial one (DeVoe et al., 2020; Lusk et al., 2015; Rivers et al., 2017). Re-establishing communication includes re-instating and relearning joint decision-making, sharing information, being responsive to each other's needs and expressing feelings and experiences (Balderrama-Durbin et al., 2015; Bowling and Sherman, 2008; Feldman and Hanlon, 2012; Greenberg et al., 2003; Knobloch et al., 2016; Knobloch and Theiss, 2012; Theiss and Knobloch, 2014; Yablonsky et al., 2016).

The second condition is connection. When employees return home, the goal is to not return to the old normal, but to establish a new emotional and physical connection (Bowling and Sherman, 2008; Cornish et al., 2014; Knobloch et al., 2016; Knobloch and Theiss, 2018; Padden and Agazio, 2013; Rivers et al., 2017). The physical connection will often happen before the emotional (Laser and Stephens, 2011). Couples who can reconnect will have better physical health, emotional functioning and appreciation, higher intimacy, lower separation rates and higher active treatment-seeking (Chandler et al., 2018; Griff et al., 2020; Knobloch and Theiss, 2012; Knobloch et al., 2016).

The last condition for role renegotiation is coping. Returning employees and their family have to use coping strategies to deal with the reintegration challenges and to create a mutual meaning for the deployment (McAdams et al., 2018). There are three ways to cope within the familial circle: problem-focused coping, emotion-focused coping and relationship-focused coping (Giff et al., 2020; Knobloch et al., 2016). Problem-focused coping involves strategies that manage practical challenges regarding routines, communications and financial situations (Giff et al., 2020; Knobloch et al., 2016). Emotion-focused coping includes strategies for seeking social support and engaging in positive emotional re-appraisal (Giff et al., 2020). Nevertheless, as earlier mentioned, deployment emotional coping mechanisms can hinder the reintegration process and the use of effective emotion-focused coping (Balderrama-Durbin et al., 2015). Third, relationship-focused coping involves behaviours that enhance communication and rekindle connections (Cogan, 2016; Giff et al., 2020; Knobloch et al., 2016). A concrete example thereof is social support. It has the capability to redefine negative situations, reduce negative emotional reactions and diminish the impact of stress (Cardozo et al., 2012; Geuzinge et al., 2020; Karstoft et al., 2019; Mankowski et al., 2015; McCormack and Joseph, 2012). Lastly, avoidance coping is associated with more significant psychological distress and lower relationship satisfaction (Giff et al., 2020).

To conclude, the employee needs to acknowledge that changes have occurred, discuss them, learn to participate again in the others' lives and appreciate the others' accomplishments (Knobloch and Theiss, 2012; Yablonsky et al., 2016). In turn, how the others participate in the employee's life and how he/she will be appreciated for his/her accomplishments, will be paramount for a positive reintegration.

3.3 Professional reintegration

Professional reintegration is defined as the resumption of various work-related and occupational roles in the organisation after a deployment (Elnitsky et al., 2017b). For a crisis service member, these roles involve daily interactions and activities in the context of a unit with peers, subordinates, co-workers and supervisors (Wooten, 2013). In the next subsections, we will discuss the influence of the challenges of the organisation where the employee returns, the peers who they work with and the individual as an employee that can, directly and indirectly, affect the reintegration process.

3.3.1 The organisation

First, the organisation where the employee returns to can have an impact on reintegration through organisational commitment which consists of three components: affective commitment (want to stay), continuance commitment (have to stay) and normative commitment (ought to stay) (Allen and Meyer, 1990). Experiencing a high level of organisational commitment can reduce the likelihood of turnover and distress and increase job satisfaction and resilience (Cardozo et al., 2012; Currie et al., 2011; Geuzinge et al., 2020). Three conditions can improve, maintain, or restore organisational commitment: organisational support, recognition and interest.

The first condition is organisational support. When employees perceive organisational support, they are likely better equipped to deal with deployment, adapt to emotional and psychological challenges and increase organisational commitment (Feldman and Hanlon, 2012). However, when an employee does not receive the support he or she desires, the sense of organisational commitment can be reduced (Feldman and Hanlon, 2012). More specific, this perceived lack of support can cause employees to question their operational value, their achievement and even their professional identity. It is associated with increased rates of PTSD, alcohol misuse, negative emotional functioning, anger and distress (Comoretto et al., 2015; Feldman and Hanlon, 2012; Harvey et al., 2011; Mankowski et al., 2015; McCormack et al., 2016; Newby et al., 2005; Van der Velden et al., 2012).

The second condition, organisational recognition, can have different forms: homecoming events, military medal ceremonies and acknowledging the contributions (Currie et al., 2011; Sorsdahl, 2010). Six studies indicated the benefits of perceived organisational recognition: fosters commitment, facilitates reintegration, validates the deployment, minimises distress, increases organisational satisfaction and enhances coping mechanisms and morale (Bolton et al., 2002; Currie et al., 2011; Greenberg et al., 2003; Feldman and Hanlon, 2012; Mankowski et al., 2015; Rubin et al., 2016).

The third condition, organisational interest, is shown by using the knowledge and skills that the employees have developed during the deployment. Research indicates that organisations tend to limit its assessment and interest in the deployment's success to maintaining a good reputation and recovering the costs (Dupont and Tanner, 2009; Newby et al., 2005). There is often no opportunity to provide feedback on what they have learned and how it can help the organisation (Dupont and Tanner, 2009). This lack of interest can impact organisational commitment, sense of purpose and well-being (Blais et al., 2009; Feldman and Hanlon, 2012).

3.3.2 The peers

Next to organisational commitment, peers play also an essential role in providing informal support due to shared work experiences and stressors, which facilitates a common understanding (Currie et al., 2011; Gil-Rivas et al., 2017; Greenberg et al., 2003). We identify three different sources of social support: the deployment unit, the co-workers at home and the supervisors at home.

The first source is the deployment unit. When the employee is assigned to a deployment, he/she becomes part of a “social” unit that shares similarities with a natural family system, which provides an environment where informal support can be given across a variety of settings (Currie et al., 2011; Denning et al., 2014; McAdams et al., 2018; Sorsdahl, 2010). This enables the employee to process his/her experiences with those who understand the burden, magnitude and significance of the deployment (e.g. Beder et al., 2011; Cornish et al., 2014; Fink et al., 2014; Finnegan et al., 2016; Heinecken and Wilèn, 2019; Knobloch et al., 2016; Lusk et al., 2015; Makinen et al., 2015; McAdams et al., 2018; Yablonsky et al., 2016). These interactions will facilitate the psychological processing by validating the experiences, giving the deployment a meaning, determining coping responses, coping with possible survival guilt and providing safety and security (Comoretto et al., 2015; Cornish et al., 2014; Hearns and Deeny, 2007; Maniken et al., 2015; Melvin et al., 2015; Verey and Smith, 2012). It can also reduce the negative consequences, such as exhaustion, distress and discourage an employee from breaking the law (Geuzinge et al., 2020; Greenberg et al., 2003; Makinen et al., 2015; Verey and Smith, 2012). Nevertheless, the unit is often dismembered at the end of the deployment, which is accompanied by a loss of immediate access to their “unit family” (McAdams et al., 2018; Sorsdahl, 2010).

Second, co-workers at home can also play an essential role in providing informal support. To facilitate the reintegration process, a returning employee needs to confide his/her experiences, discuss and reflect upon them and be listened to (Feldman and Hanlon, 2012; Scannell-Desch and Doherty, 2015). When the co-workers offer this listening ear with empathy and interest, the returnee feels valued, satisfied and trusted (Verey and Smith, 2012). It also allows the employee to share and learn from his or her experiences, implement newly learned practices and enhance their well-being (Dupont and Tanner, 2009; Verey and Smith, 2012). However, expectations of the co-workers that the employee returns directly without time to transition back into the work setting, can hinder the reintegration process (Brooks et al., 2015; Feldman and Hanlon, 2012; Saati and Wimelius, 2018; Scannell-Desch and Doherty, 2015).

The third source are supervisors who can facilitate the reintegration process in different ways (Thompson and Gignac, 2001). First, if the supervisors also have deployment experiences, they can help employees reintegrate by setting an example of self-care and work-life balance (Walsh, 2017). Second, they can reduce the risk of negative behavioural outcomes and burnout by supporting well-being and moderating distress (Cardozo et al., 2012; Fink et al., 2014). Third, supervisors guide employees through the process by identifying new strengths, placing the deployment into perspective and reducing survival guilt if needed to (Paton, 2006). All those actions are associated with lower levels of PTSD and distress and higher levels of sense of community, well-being and satisfaction (Welsh et al., 2015). However, supervisors, themselves, may experience loneliness due to the difficulties to talk to their subordinates about their feelings and experiences (Lusk et al., 2015).

3.3.3 The individual as an employee

Lastly, we examine the role of the individual as an employee. During the post-deployment stage, an employee can develop different work attitudes that influence his/her reintegration process, motivation and psychological functioning (Coetzee et al., 2010). We will discuss the cause and the positive and negative influences of different work attitudes.

There are several reasons why an employee develops negative work attitudes, which can be related to the deployment experience or to the return as an employee. These reasons can be perceived as job demands (Demerouti et al., 2001). First, reintegration can be negatively influenced by the perception of the mission, like a controversial military mission or the lack of appraisal in the civilian organisation where employees return to (Brooks et al., 2015; Heinecken and Wilén, 2019; Hollingsworth et al., 2016; Knobloch et al., 2016; Knobloch and Theiss, 2012; Wright et al., 2015). Employees can also adopt a negative attitude due to possible confrontation with force, violence and abuse when deployed (Harris and Goldsmith, 2009; Saati and Wimelius, 2018). Second, readjusting to routine work can be a challenge because of the uncertainty about the expectations and catching up to any backlog (Paton, 2006; Rubin et al., 2016; Saati and Wimelius, 2018; Wooten, 2013). Employees can also perceive the nature of their job as boring or meaningless compared to their deployment. Table 2 shows the different work attitudes, their effect and how it can present themselves. When the job demands are too high compared to the available resources, an employee can develop eventually lasting negative attitudes toward his or her work (Currie et al., 2011).

Employees can also develop positive attitudes that enhance their reintegration process and performance (Knobloch et al., 2016; Saati and Wimelius, 2018). This is especially the case when the job demands are in balance with the resources of an employee (Currie et al., 2011). In addition, the deployment and more specifically, the positive appraisals of their work contribution can help the employee to promote various work related effects (Table 2).

To conclude, reintegration research has almost exclusively focused on individual and interpersonal reintegration, neglecting professional reintegration and its specific challenges (N = 8). In general, employees who experience professional difficulties may develop lasting negative attitudes, which in turn can lead to general negative appraisals of the organisation or leaving it (Blais et al., 2009). Nevertheless, the influence of organisational commitment can counter these effects and hence facilitate positive reintegration outcomes. This is also the case for the positive influence of peers, co-workers and supervisors.

3.4 What do we know about the process of reintegration?

A completed reintegration process takes time, is individual and its duration varies thus with each employee (Elliott, 2015; Scannell-Desch and Doherty, 2015). Completed reintegration occurs when all roles, responsibilities and routines have been renegotiated (Melvin et al., 2015; Padden and Agazio, 2013). In the next subsections, we will discuss the post-deployment timeframe and the different reintegration phases we identified across the 104 studies. The post-deployment timeframe is influenced by personal characteristics, skills, past and recent experiences and challenges, coping strategies and the level of physical and mental health functioning (Doyle and Peterson, 2005; Thompson and Gignac, 2001; Wooten, 2013). Across the literature, researchers have identified several reintegration timeframes (Figure 3). In general, five studies state that reintegration may last for 3–6 months (Knobloch et al., 2016; Morse, 2006; Padden and Agazio, 2013; Pincus et al., 2001; Rivers et al., 2017). Two studies suggest that it can take up to three months to adapt back to the home environment (Heinecken and Wilén, 2019; Tobin, 2015). Rivers and colleagues (2013) state that the acute reintegration period may last from 3–9 months, but can cause strain for 12–18 months.

During reintegration, employees face different challenges that can be placed into different reintegration phases. These phases are dynamic and impacted by specific challenges on the individual, interpersonal and professional dimensions of the reintegration process (Elliott, 2015; Miller and Warner, 2013; Wooten, 2013). Due to the flexibility of roles and needed adjustments, the reintegration process is difficult to define and circumscribe. However, the analysis of the literature in our systematic review points out three phases that can reflect an employee's experiences during that time. These phases are individual and each person proceeds through them at his/her own pace (Rivers et al., 2013). Some can move through them faster, while others are stuck in a specific phase and phases may overlap (Sorsdahl, 2010).

Phase 1. Nine studies indicate that reintegration starts with a celebratory phase marked by joy, excitement, relief and harmony (Elliott, 2015; Knobloch et al., 2016, 2019; Knobloch and Theiss, 2011, 2012; Laser and Stephens, 2011; Milliken et al., 2007; Padden and Agazio, 2013; Pincus et al., 2001). During this period, employees report a high level of well-being, optimism and positive affect (Hollingsworth et al., 2016; Knobloch and Theiss, 2012). These feelings can be enhanced by a positive homecoming experience, holidays and fun activities (Bowling and Sherman, 2008; Heinecken and Wilén, 2019). Nonetheless, the first few weeks home can also be marked by misunderstanding and partner interference, which are associated with reintegration and mental health difficulties during the first three months (Knobloch et al., 2013; Knobloch-Fedders et al., 2020). Interference occurs when individuals constantly disrupt each other (Heinecken and Wilén, 2019; Knobloch and Theiss, 2018; Yablonsky et al., 2016). In spite of that, these changes and potential mental health symptoms can be overlooked, overshadowed or minimised by people's happiness and sense of relief by returning home (Bliese et al., 2007; Bowling and Sherman, 2008). On the one hand, some mental health symptoms are not yet present or do not hinder the reintegration process. On the other hand, employees do not want to share their initial burden because they fear it will delay their homecoming (Bliese et al., 2007; Laser and Stephens, 2011). Researchers are uncertain how long this initial “honeymoon period” is, but one study suggests that this period may extend up to one month (Bliese et al., 2007).

Phase 2. However, after the initial excitement, the reality of reintegration may set in and individuals may realise that some routines, responsibilities, and roles may have changed during deployment (Elliott, 2015; Knobloch et al., 2016; Melvin et al., 2015; Padden and Agazio, 2013). Employees find themselves in a transitional phase where they are in between two roles and move through and try to understand the changes and challenges on the individual, interpersonal and professional dimensions (Knobloch et al., 2016; Lusk et al., 2015; Pincus et al., 2001; Sorsdahl, 2010). This move can be categorised into different themes: figuring it out, feeling trivial, understanding the changes, adapting to the changes and renegotiating the changes (Albuquerque et al., 2018; Elliott, 2015; Sorsdahl, 2010). Nine studies report several consequences of these themes: resistance, frustration, awkwardness, estrangement, distress, conflict and grief for their old self (Elliott, 2015; Heinecken and Wilén, 2019; Knobloch et al., 2019; Knobloch and Theiss, 2014; Milliken et al., 2007; Padden and Agazio, 2013; Theiss and Knobloch, 2014). Regarding the duration of phase 2, there is no consensus among researchers (Figure 4). In general, researchers state that an increase of mental health problems often occurs after a certain period of time (Banwell et al., 2016; Bliese et al., 2004, 2007; Cardozo et al., 2012; Hollingsworth et al., 2016; Knobloch et al., 2019; McCormack et al., 2016; Milliken et al., 2007). This increase may be attributed to a delay in the emergence and perception of change and conflict following homecoming (Hollingsworth et al., 2016). Research also revealed that the length of time at home is positively associated with relational uncertainty, interference from partners and relationship dissatisfaction (Knobloch and Theiss, 2011, 2014; Knobloch et al., 2020).

Phase 3. After the second phase, there is a decrease in reported challenges of emotional intimacy, support, readjustment to daily life and conflict (Knobloch-Fedders et al., 2020). Elliott (2015) states that employees exit phase two when they acknowledge the changes and attribute a new meaning to their deployment and reintegration experiences. Nevertheless, several elements can hinder an employee's entrance to this phase. First, redeploying before complete reintegration can contribute to psychological distress and social isolation (McCormack and Joseph, 2012; McCormack et al., 2016). In addition, the future plans for a new deployment influence the reintegration phases: if an employee only has four months at home, they may show different reintegration phases (Bliese et al., 2007). Third, long-term reintegration difficulties can occur when an employee has low resilience, high exposure to combat, stressful experiences and a lack of social support (Cunningham et al., 2014).

In sum, we can identify three distinct phases across the literature: celebratory phase, transitional phase and stabilisation phase. Even though these phases are individual and each person moves through them at his/her own pace, we observe that each phase may have a distinct timeframe.

4. Discussion

In this review, we addressed three research questions: (1) how is the reintegration process conceptualised and measured in the existing literature? (2) What dimensions are associated with the reintegration process? (3) What do we know about the process of reintegration in terms of timing and phases? In general, we found that researchers tend to investigate only one dimension of reintegration, to consider reintegration as an outcome and to overlook positive outcomes of reintegration. This fragmentation around the construct of reintegration results in a lack of a consensual model to describe and study this phenomenon. This has several consequences. First, researchers have a lack of understanding of the generic dimensions of reintegration that they want to clarify. Second, measurement tools proliferation is a corollary of this lack of understanding. Third, even though many researchers recognise the existence of the three dimensions of reintegration – the individual, interpersonal and professional dimensions (e.g. Beder et al., 2011; Currie et al., 2011; Denning et al., 2014; Elnitsky et al., 2017a, b; Fikretoglu and McCreary, 2010; Lubens and Bruckner, 2018; McCreary et al., 2014; Milliken et al., 2007; Padden and Agazio, 2013; Rivers et al., 2017; Sorsdahl, 2010; Wooten, 2013), studies still often define reintegration as a “static process” or as an “outcome”. Nevertheless, we found that conceiving and measuring reintegration as a “static process” or as an “outcome” greatly limits the research scope of investigating reintegration as a dynamic process that evolves over time with dimensions and phases entailing distinct challenges.

Thus, we join Cogan (2016) and Elnitsky and colleagues (2017a, b) in stating that reintegration should be seen as a process that needs to be experienced and managed rather than a set of concrete outcomes that need to be achieved. It is not a linear phenomenon fixed between two points in time. In an effort to integrate the results of this systematic literature review and to address these fragmentations, in the following lines, we applied Bronfenbrenner's social-ecological framework (1979, 2005) to the understanding of past reintegration research. Our focus lies on the three main dimensions of the microsystem: individual, interpersonal and professional. By outlining these different dimensions, their specific challenges, and their detrimental or beneficial effects on the individual in this social-ecological framework (Figure 5), future researchers can investigate reintegration as a multi-dimensional, dynamic, dual process rather than with a mono-domain, static and problem-focused perspective. Our process-model helps to identify interactions that determine how an employee experiences the reintegration process. They also help to understand why the experience of returning home can be paradoxical, with both positive and negative cognitions, affects and behaviours that arise simultaneously. Below, we discuss three main observations regarding reintegration as a process: the existence of several types of interactions within the framework, the acknowledgement of paradoxical experiences for the individual and the lack of research regarding police officers and NGO personnel. In the following lines, we also propose our reflection about what the end-state of reintegration is. First, we distinguish three types of interactions that can occur during reintegration: spill-over interaction, interaction within a dimension and interaction within a challenge.

A spill-over interaction means that challenges of one dimension interacts with challenges of another dimension. The dashed lines in Figure 5 indicate the ability of dimensional challenges to permeate and affect experiences in another dimension within the socio-ecological framework of an individual. For example, identity disruption on the individual dimension can hinder interpersonal reintegration because the employee fails to recover a role and an identity within the family (e.g. Balderrama-Durbin et al., 2015; Elliott, 2015; Rubin et al., 2016). Conversely, individual resilience and coping can facilitate communication and renegotiating family connections (e.g. Eisen et al., 2014; Knobloch and Theiss, 2018; Wesemann et al., 2018).

An interaction within a dimension means that some challenges can hinder or facilitate the process at the same time. For example, a family imposes demands to re-adapt to familial roles (Baptist et al., 2011; Hollingsworth et al., 2016), but at the same time provides social support to reintegrate (e.g. Cederbaum et al., 2017; Fink et al., 2014; Yablonsky et al., 2016). Similarly, the organisation at home can enable an employee to process his/her experience and place them within their new roles and routines (e.g. Beder et al., 2011; Cornish et al., 2014; Fink et al., 2014), but at the same time imposes demands to resume work tasks without having time to transition back or receiving recognition, support, or interest (Brooks et al., 2015; Currie et al., 2011; Feldman and Hanlon, 2012; Saati and Wimelius, 2018; Scannell-Desch and Doherty, 2015).

An interaction within a challenge means that one specific challenge within a dimension can have both a detrimental and beneficial effect. For example, at the professional level, co-workers at the home unit can provide social support; however, when not provided, it can enhance feelings of frustration, anger and disconnection (e.g. Brooks et al., 2015; Finnegan et al., 2016; Verey and Smith, 2012). At the individual level, if the employee is unable to use adaptive coping strategies, he/she is more prone to use maladaptive strategies that can hinder the reintegration process and are ineffective in the long run (Brooks et al., 2015; Chandler et al., 2018; Comoretto et al., 2015; Dattilo, 2015; Eisen et al., 2014; Mattock et al., 2012; Miller and Warner, 2013; Thompson and Pastò, 2003; Taff et al., 2016; Wright et al., 2015).

Second, while the entry point of reintegration is relatively easy to define (the moment the employee is leaving the deployment to the moment he/she arrives in his/her country), the point out is more a subject for debate. We suggest that the end-state of the reintegration process is when individuals reach a new homeostasis, new routines and new roles which may or may not be functional and/or adaptive. Getting to this point can feel paradoxical to the individual. This means that employees can encounter negative and positive reintegration experiences at the same time. Due to the fragmented research, the timeframe of the reintegration process is difficult to define and circumscribe. However, the analysis of the literature in our systematic review points out to three phases (celebratory phase, transitional phase and stabilisation phase) that can reflect an employee's different experiences during that time. The first, “celebratory”, phase is often marked by a high level of well-being, optimism and positive affect (Hollingsworth et al., 2016; Knobloch and Theiss, 2012). However, during the second, “transitional”, phase, individuals discover that routines, roles and responsibilities need to be renegotiated. This phase can be marked by relational turbulence and grief for their old self as they knew it before and during deployment (e.g. Elliott, 2015; Heinecken and Wilén, 2019; Knobloch et al., 2019; Knobloch et al., 2020; Knobloch and Theiss, 2011; Knobloch and Theiss, 2014; Knobloch and Theiss, 2018; Milliken et al., 2007; Padden and Agazio, 2013; Theiss and Knobloch, 2014). The last, “stabilisation”, phase occurs when employees acknowledge the changes, attribute a new meaning to their deployment and reintegration experiences and attain a new routine with possible new roles (Elliott, 2015). Until then, the post-deployment stage will be perceived as stressful (Brenner et al., 2015; Knobloch and Theiss, 2018). However, these phases still need further research to identify phase-specific challenges and their timeframe. We also note that despite the existence of positive experiences, those remain largely unaddressed in the literature.

Our third and last observation is related to the populations previously included in studies about reintegration. Remarkably, we found that very little research has been done on the reintegration experiences of the personnel of NGOs (N = 13) and police officers (N = 5). Even though the reintegration research of these services is limited, it is still necessary to include these studies (N = 18) in our review since they offer us essential insights into the reintegration process. First, seven studies put into words how individual capabilities (identity and resilience) influence the reintegration process (Brooks et al., 2015; Campbell and Warner, 2016; Comoretto et al., 2015; Fahim et al., 2014; Makinen et al., 2015; Rubin et al., 2016; Tobin, 2015). Second, some studies also reveal how an individual experiences reintegration and role renegotiation with friends (Albuquerque et al., 2018; McCormack and Joseph, 2012; Rubin et al., 2016). Third, 15 of the 18 studies shed light on the professional reintegration experiences across the three sources: the organisation, the peers and the individual as an employee (e.g. Albuquerque et al., 2018; Brooks et al., 2015; Cardozo et al., 2012; Comoretto et al., 2015; Drodge and Roy-Cyr, 2003; Dupont and Tanner, 2009; Geuzinge et al., 2020; Hearns and Deeny, 2007; Makinen et al., 2015; McCormack and Joseph, 2012; McCormack et al., 2016; Rubin et al., 2016; Paton, 2006; Saati and Wimelius, 2018; van der Velden et al., 2012). Thereafter, they offer also key information on how the reintegration process and its timeframe can be conceptualised (Abuquerque et al., 2018; Cardozo et al., 2012; McCormack and Joseph, 2012; McCormack et al., 2016).

Concluding on our observations, the social-ecological framework and our review reveal that the end-state of reintegration is a result of how the different dimensional challenges and their effect interact with each other. Thus, the final homeostasis is not a function of one of the deployment experiences or of one of the specific reintegration dimensions, but of how experiences in the different dimensions interact with each other (Elnitksy et al., 2017a; Paton, 2006; Violanti and Paton, 2006). In the following lines, we elaborate on a number of practical recommendations for managers and mental health practitioners. Because the number of high-risk countries keeps growing and the expatriation of corporate employees grows as well (Fee and McGrath-Champ, 2017; Faeth and Kittler, 2020), our findings and recommendations could be applicable to this population too. Indeed, in their review on expatriates in hostile environment, Faeth and Kittler (2020, p. 3) define hostile environments as locations in which individuals are exposed to an above-average presence of human-made threats in the form of intentional violence or the lack of essential resources. This feature is similar to what military personnel, police officers and NGO personnel experience. In this sense, what we have learned from this literature review could be applicable to the reintegration of corporate employee coming back from a hostile environment.

4.1 Practical implications

The reintegration process can be turbulent. However, based on the synthesis of the findings, we identify several conditions that facilitates reintegration across the dimensions and challenges of the social-ecological framework. We formulate our recommendations for the management and mental health practitioners to help them develop psycho-information and psycho-education interventions for individuals returning home from a hostile environment. These recommendations aim at helping an individual reintegrate, find his/her place again with new routines and a functional homeostasis. The first three recommendations are based on the individual capability of “coping”. The three recommendations can be divided into three types of interventions, one with cognitive relevant, one with behavioural-relevant and the last one with behavioural-related outcomes. The last recommendation addresses the principle of “leisure”.

First, we advise practitioners to focus on facilitating and promoting the individual capability of “coping”. A first way to do so is to inform individuals about what adaptive coping strategies are and how these can be used in concrete reintegration settings. Correspondingly, while learning about the effects of maladaptive coping strategies, employees may be more prone to recognising warning signals (e.g. binge eating or drinking, compulsive spending) and adopt more adaptive behaviours (Mattocks et al., 2012; Thompson and Pastò, 2003). This recommendation is centred on cognitive relevant outcomes attained by a psycho-information intervention. Still, in informing about coping, practitioners and management need to keep in mind that couples that combine the reintegration process with stressful family changes, like moving out, for example, may deplete their coping resources more quickly (Knobloch-Fedders et al., 2020). In addition, if employees feel affectively overwhelmed while re-establishing new routines, they might cope with brutal attempts to regain control, resulting in domestic violence and abuse if aggressive behaviours lies in their nature (Bowling and Sherman, 2008). Thus, management and practitioners need to be alert for these signals that may deplete adaptive coping strategies and stimulate maladaptive ones.

A second way to facilitate and promote coping is to learn employees how they can use these adaptive coping strategies to ease individual and interpersonal reintegration (Balderrama-Durbin et al., 2015; Chandler et al., 2018; Cogan, 2016; Dattilo, 2015; Giff et al., 2020; Knobloch et al., 2016 Mattocks et al., 2012; McAdams et al., 2018; Miller and Warner, 2013; Taff et al., 2016; Thompson and Pastò, 2003; Wright et al., 2015). The main principle of this recommendation is behavioural-relevant psycho-education. Because of the spill-over interactions discussed above, creating an intervention about coping at the individual level can affect the two other dimensions (interpersonal and professional). Hence, the management and mental health practitioners can facilitate successful reintegration by increasing the individual's resources, minimising stress, handling emotions, creating a new meaning and renegotiating new roles (Brooks et al., 2015; Eisen et al., 2014).

Another practical recommendation is related to relationship-focused coping (behavioural-related outcomes), more specifically on social support in the form of a homecoming event with partners, family, friends and the organisation (Scannell-Desch and Doherty, 2015). Homecoming is often presented as a mere happy and emotional reunion, yet studies indicate that the reception of the social networks and the organisation influence how an employee experiences reintegration (Bolton et al., 2002; Mankowski et al., 2015). In particular, a positive homecoming is associated with better adaptation (Bolton et al., 2002; Mankowski et al., 2015), while a lack of perceived support might increase experienced physical, behavioural and psychological health issues (Balderrama-Durbin et al., 2015; Bolton et al., 2002; Cederbaum et al., 2017; Eisen et al., 2014; Sorsdahl, 2010). An example of a lack of perceived support is when organisations do not systematically recognise employee's effort, offer support, perceive the partaking as a burden and fail to take into account the deployment experiences in the promotion procedures (Albuquerque et al., 2018; Castro et al., 2015; Cornish et al., 2014; Dupont and Tanner, 2009; Fink et al., 2014; Hearn and Deeny, 2007; Heinecken and Wilén, 2019; Saati and Wimelius, 2018). The observations of the celebratory phase imply that the effect of homecoming interventions immediately after returning home could be limited in time, since the highest distress is accounted for 3–6 months after returning home (Bliese et al., 2004; Morse, 2006; Padden and Agazio, 2013; Pincus et al., 2001; Rivers et al., 2017). Thus, the findings of our review suggest that reintegration is better fostered by showing regular acts of recognition, providing opportunities to show interest and receive feedback from employees and being transparent about the offered support (Currie et al., 2011; Dupont and Tanner, 2009). Our review also indicates that homecoming events and psychological screening may be more helpful between three and six months' post-reintegration relative to being conducted immediately.

The last recommendation is related to leisure. Stimulating leisure activities can facilitate reintegration on the individual and interpersonal dimensions, affecting in turn the third dimension by a spill-over interaction. On the individual dimension negative individual reintegration experiences can be countered through different interventions that can enhance positive experiences and lower the level of perceived stigma. For example, promotion of leisure can help an employee to find a new daily living arrangement, to cope with feelings of isolation and disconnection, or to channel adrenaline-seeking behaviour legally (Blais et al., 2009; Bowling and Sherman, 2008; Brenner et al., 2015; Elliott, 2015; Elnitsky et al., 2017b; Fink et al., 2014; Knobloch and Theiss, 2012; McCreary et al., 2014; Rivers et al., 2017; Rubin et al., 2016; Thompson and Gignac, 2001; Thompson and Pastò, 2003). The promotion of leisure can also help an employee with identity integration by reflecting on events, making meaning of them and finding a place for them within their identity (Beder et al., 2011; Fikretoglu and McCreary, 2010). Second during interpersonal reintegration a couple or family can stimulate connection and communication by engaging in shared activities (Chandler et al., 2018).

4.2 Theoretical implications

Although the increased attention on reintegration in the period 2001–2021 has contributed to essential knowledge, there are still gaps and misconceptions in the literature. First, in our review, we tried to provide a social-ecological framework that includes all the possible challenges that an employee might face while reintegrating. Besides, we tried to nuance the different reintegration experiences and their possible existence across the crisis service sectors. In other words, each reintegration process will be individual, that is, characterised by individual specific challenges across the three dimensions of reintegration and along the phases. Therefore, employees (military service members, non-governmental personnel, or police officers) might experience hostility, disconnection, reckless behaviour, or estrangement from their children and family upon return, but those are not systematic challenges of the reintegration process. Thus, a completed reintegration process takes time, is individual, and its duration varies for each employee (Elliott, 2015; Scannell-Desch and Doherty, 2015). We need to acknowledge that even though the reintegration process might be similar, the faced challenges and the individual reactions of the employee to them may differ. Hence, the individual level variance might be larger than the sectoral variance. Therefore, future research needs to further map the individual variation in the reintegration process and experiences for all crisis service members (military service members, non-governmental personnel, police officers) and also accounts for the different experiences during the deployment and post-deployment stage.

Second, there is often a tendency to focus on creating new interventions that facilitate reintegration relying on non-natural systems. However, many reintegration challenges can be facilitated through settings, structures and dimensions in which returning employees function naturally (see the social-ecological framework, Elnitsky and Kilmer, 2017c; Gil-Rivas et al., 2017). Future research and interventions need to focus more on enhancing the existing resources within individuals, families, organisations and communities. Due to the embeddedness of reintegration in several dimensions, if you target interventions at only one level, they will impact the functioning of the other levels (Bronfenbrenner, 1979; Elnitsky et al., 2017a).

Third, the identification of the three dimensions provides opportunities for conceptualising the reintegration process, its dimensional indicators and its measurement. In the literature, several indicators and measurements have been described but taken together none of them captures the entire reintegration process (for example Karstoft et al., 2019). Future research must incorporate methods that capture the multiple reintegration dimensions in order to develop a comprehensive view of the process. This can enable researchers to detect psychological, behavioural and physical signs of distress and facilitate access to professional psychological help (Dimoff and Kelloway, 2016). In addition, considering reintegration as a process may help health providers identify the most effective timing of measurements and interventions to facilitate the reintegration process.

Fourth, there is a lack of research on specific reintegration challenges within and between phases (Blais et al., 2006; Knobloch-Fedders et al., 2020). Future research needs to indicate specific needs and challenges for each phase that an employee goes through and we need to mark scientifically the differences between individual reintegration trajectories that cover reintegration dimensions and challenges (Coetzee et al., 2010; Rivers et al., 2013; Wooten, 2013).

4.3 Limitations

We can identify three limitations to our review. First, the selection procedure was executed by one author. This can imply that the selection is influenced by the author's viewpoints. However, to counter this bias, a second reviewer reviewed 20% of the results on each iteration of the selection. Second, we pre-registered our protocol on the Open Science Framework before executing our search. Nevertheless, when using the Boolean phrase, we had too many irrelevant results. So, we needed to reconsider our Boolean phrase and narrow our range of results (Keathley et al., 2016; Page et al., 2021; Randolph, 2009; Wanyama et al., 2022). Third, to obtain a global set of relevant reintegration literature, we chose specific selection criteria. We solely selected reintegration literature that focused on the return of active-duty crisis service employees. This meant that we excluded studies focusing on veterans, reserve army and national guard units even though they also discussed the topic of reintegration and experienced reintegration challenges. Studies that focused on veteran reintegration were read carefully as veterans have a double meaning. A veteran has either completed a mission or is retired and therefore no longer in active duty. It is also possible that other studies investigating reintegration were not included because they did not explicitly refer to our included search terms. Moreover, we tried to reduce this bias by using many different search terms (e.g. by using search terms such as “return to home”, “post mission” or “after deployment”).

5. Conclusion

This review was the first to systematically identify and report on the literature concerning reintegration of crisis service employees. We applied Bronfenbrenner's social-ecological framework with three main dimensions of interest (individual, interpersonal and professional) to review 104 studies. This enabled us to code, categorise and address the involvement of the different dimensions and challenges, their interactions and their possible detrimental or beneficial effect on the reintegration process. Our review and framework illustrates that this involvement can be simultaneous and paradoxical. This suggests that reintegration is a dual process, with both positive and negative experiences. Yet in the period of our review (1995–2021), different dimensions, mainly individual and interpersonal, were addressed separately, each with their specific focus, often without capturing the whole reintegration process and often letting aside the positive aspects of returning home after a deployment. We described a reintegration process with different phases that take place during the post-deployment stage: the celebratory phase, the transitional phase and the stabilisation phase. Each phase is associated with new challenges, which can be threats or opportunities to grow, but researchers are still debating about the post-deployment timeframe in which these three distinct phases occur. Nevertheless, these phases still need further research to identify phase-specific challenges and their timeframe. To conclude, with the present study, we intended to move away from a fragmented, mono-domain, static and problem-focused perspective on reintegration. By providing a new integrative framework, we hope to encourage researchers and practitioners to view reintegration as a multidimensional, dual and dynamic phenomenon that evolves over time.

Figures

Figure 1

The review's integrated vision of the Bioecological model (2005) and the Social-Ecological framework (1979) of Bronfenbrenner

Figure 2

PRISMA 2020 flow diagram for new systematic reviews which included searches of databases, registers, and other sources

Figure 3

The different post-deployment timeframes

Figure 4

The different durations of phase 2

Figure 5

The social-ecological framework, its dimensions, and challenges

Table 1

The individual reintegration experiences

Experience	Negative	Positive
Emotional reintegration	Anxiety, existential distress, conflicting emotions (hostility, disconnection, isolation, helplessness), loss of motivation, irritation, anger, resentment, suicidal thoughts, loss of identity	Strengthened relationships, Sense of purpose, sense of pride, broadened life perspective, personal growth, increased self-esteem, new priorities
	Adler et al. (2011), Blais et al. (2006), Blais et al. (2009), Balderrama-Durbin et al. (2015), Bowling and Sherman (2008), Brenner et al. (2015), Cardozo et al. (2012), Cornish et al. (2014), Danish and Antonides (2013), Elliott (2015), Feldman and Hanlon (2012), Kaplow et al. (2013), Knobloch et al. (2013), Knobloch et al. (2019), Lusk et al. (2015), Mankowski et al. (2015), McCreary et al. (2014), Rubin et al. (2016), Saati and Wimelius (2018), Thompson and Gignac (2001), Thompson and Pastò (2003), Wright et al. (2015)	Baptist et al. (2011), Blais et al. (2006), Brenner et al. (2015), Feldman and Hanlon (2012), Fikretoglu and McCreary (2010), Knobloch et al. (2016), Knobloch and Theiss (2018), McCreary et al. (2014), Newby et al. (2005), Rivers et al. (2013), Thompson and Gignac (2001), Thompson and Pastò (2003), Tobin (2015)
Physical reintegration	Increased sensitivity to stressful triggers, hypervigilance, hyperactivity, sleeping problems, adjust to daily arrangements, changes in eating, sleeping, and exercising habits, exhaustion, compassion fatigue	Physical exercise and leisure
	Baptist et al. (2011), Blais et al. (2009), Bowling and Sherman (2008), Brenner et al. (2015), Cornish et al. (2014), Drodge and Roy-Cyr (2003), Elliott (2015), Heinecken and Wilén (2019), Knobloch and Theiss (2012), Laser and Stephens (2011), Makinen et al. (2015), Mattocks et al. (2012), Padden and Agazio (2013), Rivers et al. (2017), Rubin et al. (2016), Scannell-Desch and Doherty (2015), Wooten (2013)	Chandler et al. (2018), Dattilo (2015), Miller and Warner (2013), Taff et al. (2016)
Behavioural reintegration	Substance misuse, aggression, adrenaline-seeking behaviours, suicide attempts, antisocial behaviour, hostility, perception of stigma	Leadership ability, new strengths and skills, effective communication, contribute to a greater good, friendships
	Blais et al. (2009), Bowling and Sherman (2008), Cogan (2016), Cornish et al. (2014), Danish and Antonides (2013), Elnitstky et al. (2017b), Finnegan et al. (2016): Lusk et al. (2015), McCreary et al. (2014), Rivers et al. (2013)	Baptist et al. (2011), Knobloch et al. (2016), Newby et al. (2005)
Spiritual reintegration	Questioning religious beliefs	New strength, emotional support, facilitate understanding, stimulate coping
	Guilt, conflicting values
	Danish and Antonides (2013)	Baptist et al. (2011), Mankowski et al. (2015), Miller and Warner (2013), Wooten (2013)

Table 2

The different work attitudes, their effect and how they can present themselves

Work attitudes	Effect	References
Negative	Higher risk for depression and burnout, Decreased organisational commitment, Feelings of loss, Reduced attention to professional norms, Problems with punctuality, Poor respect for the chain of command, Social isolation, Absenteeism, Sense of unfulfilment, (Sudden) Withdrawal or resignation, Increased turnover intentions	Albuquerque et al. (2018), Cardozo et al. (2012), Coetzee et al. (2010), Cogan (2016), Currie et al. (2011), Danish and Antonides (2013), Drodge and Roy-Cyr (2003), Dupont and Tanner (2009), Fikretoglu and McCreary (2010), Paton (2006), Walsh (2017)
Positive	New insights into their job, Sense of achievement and pride, Stronger management skills, Belief that they can better structure their workload and handle the future, Increased well-being, health, and self-esteem, Enhanced management skills, Professional growth, Increased affective commitment, Increased cultural awareness	Blais et al. (2009), Dupont and Tanner (2009), Feldman and Hanlon (2012), Knobloch et al. (2016), Paton (2006), Rubin et al. (2016), Saati and Wimelius (2018), Thompson and Pastò (2003), Tobin (2015), Wooten (2013)

Table A1

Instruments that measure reintegration

Instrument	Description	# items
Deployment Risk and Resilience Inventory (DRRI; Vogt et al., 2013)	Self-report measure based on a biopsychosocial framework that assesses a range of deployment and post-deployment risk and resilience factors. Scales address prior stressors; childhood family environment; deployment preparedness; difficult living and working environment; concerns about life and family disruptions; general harassment; sexual harassment; perceived threat; unit support; combat experiences; aftermath of battle; exposures; post-deployment social support; and post-deployment stressors.	17 items
Post-deployment transition home (Fink et al., 2014)	Self-report measure that address the post-deployment outcome by asking one question: “My transition from combat to home has gone well”.	1 item
Iraq Readjustment Inventory (IRI; Katz et al., 2007)	Self-report measure that assesses social readjustment, deployment experiences, and deployment concerns. It measures three factors: global measure of readjustment, social readjustment, and concerns about Iraq.	16 items
Post-deployment Readjustment Inventory (PDRI; Katz et al., 2010)	Self-report measure that is an extension to the IRI. It represents seven/six domains: global readjustment, career challenges, health concerns, intimate relationship problems, social difficulties, deployment concerns and PTSD symptoms.	36 items
Postmission altruistic identity disruption questionnaire (PostAID/Q; McCormack et al., 2016)	Self-report questionnaire assesses the complex psychosocial challenges of humanitarian aid work returnees. It was designed with the aim to guide organisations in the psychosocial support, to assist humanitarian aid personal to identify inter/intra personal, environmental, and organisational influences on their psychosocial well-being, and to assist organisations in assessing redeployment readiness.	18 items
Post-Deployment Health Assessment (PDHA; DOD, 2006, 2008)	Questionnaire that is taken within 30 days after return. The purpose is to identify any physical and/or psychological health issues, concerns, or symptoms that are common following a deployment. It assesses traumatic stress, depression, suicidal ideation, interpersonal conflict, interpersonal aggressive ideation, physical symptoms, and environmental exposures. The first part is completed by the employee, and is followed by a face-to-face session with a health care provider.	/
Post-Deployment Health Re-Assessment (PDHRA; DOD, 2006 and 2008)	The Post-Deployment Health Reassessment (PDHRA) is a health screen designed to protect and evaluate the health of those returning from combat and completed between 90 and 180 days after they have returned to their work.	/
Post-Deployment Reintegration scale (PDRS; Blais et al., 2003, 2006)	Self-report measure that assesses positive and negative experiences of military personnel in work, family, and personal domains.	36 items
Combat-to-home transition scale (C2HTS; Adler et al., 2011a, b)	Self-report measure that assesses the positive and negative aspects of returning home from combat. It consists of four dimensions: Benefit, Appreciation, Anger/Alienation, and Guilt/Remorse.	16 items
Community integration questionnaire (CIQ; Willer et al., 1994)	Self-report measure that assess different aspects of home and social activities, and work or school activities of individuals recovering from a TBI. It represents three global domains: home integration, social integration, and productive activity.	15 items
Community integration measure (CIM; McColl et al., 2001)	Self-report measure that assesses participation and connections of individuals with TBI in the environment. It includes assimilation, support, occupation, and independent living.	10 items
Community reintegration of service members (CRIS. Resnik et al., 2009)	CRIS is a self-report multidimensional measure consists of three subscales: extent of participation, perceived limitations, satisfaction with participation. They assess nine domains of participation: knowledge, general tasks, communication, mobility, self-care, domestic life, relationships, major life areas, and community, social, and civic life.	152 items
Military to Civilian questionnaire (M2C-Q; Sayer et al., 2011)	Self-report measure that assesses post-deployment community reintegration. More specific, it measures general difficulty in readjusting to civilian life following deployment by assessing social and health behaviours, interpersonal relationships, productivity, community participation, self-care, leisure, and perceived meaning in life.	16 items

Table A2

Overview of the mentioned models

Model	Description	Dimension
Contextual Model of Family Stress (CMFS; Boss, 2002; Boss et al., 2016)	It highlights the role of internal and external situations that may hinder or facilitate the family's resources and perceptions in adapting to stressors (Hollingsworth et al., 2016). The model identifies several external contexts that influence families depending on the available resources and perception of the stressors.	Family
Co-Parenting framework (DeVoe et al., 2020)	It identifies transitions that employees and their partners face while navigating the logistical and emotional changes associated with co-parenting during the phases of the deployment cycle.	Family
Relational turbulence model (Knobloch and Theiss, 2011)	The model states that people experience upheaval during transition because relationship changes emerge from relational uncertainty and partner interference.	Family
ABC-X model (McCubbin and Patterson, 1983)	The model proposes that a couple's available resources and their perceptions of the stressors and resources will predict whether they will experience a family crisis or state of upheaval.	Family
Couple adaptation to traumatic stress (CATS; Nelson Goff and Smith, 2005)	The model states that the adaptation to traumatic stress is influenced by the interaction of the individual functioning level, predisposing factors, resources, and couple functioning.	Family
Family attachment network model (Riggs and Riggs, 2011)	The model frames various factors that can affect the subjective well-being of family members during and after deployment.	Family
Multidimensional Grief Theory (Layne et al., 2013; Kaplow et al., 2013)	The model is based on the assumption that both maladjustment and positive adjustment can occur within each grieving stage. It consists of three domains: separation distress, existential distress, and distress over the circumstances.	Individual