Introduction

Refugees are people who have been forcibly displaced from their countries by war, violence, conflict, or persecution. Globally, the number of refugees nearly tripled in the past dozen years, from 10.5 million in 2010 to approximately 27 million in mid-2022 (United Nations High Commissioner for Refugees [UNHCR]). Refugee resettlement is one durable solution pursued by the UNHCR as part of its core mandate. Resettlement is the relocation of a refugee from a country of asylum (usually a neighboring country) to a third country that provides them permanent residency and the opportunity for eventual citizenship (UNHCR, 2022b, 2022c). In 2022, refugees were resettled in 25 countries, the top five being the USA, Canada, Germany, Australia, and Sweden (UNHCR, 2022d). An estimated 1.5 million refugees currently need resettlement (UNHCR, 2022d), and this number will increase in years to come due to continuing conflicts and human rights violations worldwide.

Due to stressors and traumas experienced before, during, and after migration, refugees experience many challenges in resettlement, including risks to their physical and mental health. In resettlement, refugees often experience physical health disparities due to social determinants such as low health literacy, linguistic and cultural barriers, and institutional discrimination (Harsch & Bittlingmayer, 2018; World Health Organization, 2022). Regarding mental health, a recent meta-analysis of studies on refugees, mostly in resettlement countries, estimated high prevalence of post-traumatic stress disorder (31%) and depression (32%), which appear to persist for many years post-migration (Blackmore et al., 2020). To help refugees enhance their well-being, become economically self-sufficient, and integrate with their new environment, governmental and non-governmental organizations partner to provide resettlement services such as cultural orientation, language and vocational training, employment assistance, and physical and mental health care, among others.

In recent years, resettlement organizations and researchers have called for implementing evidence-based practice in service provision (Abubakar et al., 2018; Cheng et al., 2018; Fennig, 2021; Griswold et al., 2018; Sijbrandij, 2018; UNHCR, 2019). To further this aim, in 2020, the US Office of Refugee Resettlement funded the development of an electronic database of evidence-based interventions specifically for refugee resettlement (Switchboard, 2023a). This database, which prioritizes meta-analyses, systematic reviews, and randomized controlled trials, to date contains over 200 primarily peer-reviewed articles from resettlement countries around the world, together with associated evidence summaries. This database and its evidence summaries, along with increasing open-access availability, social media, webinars, and similar technological developments, have vastly increased the dissemination of knowledge about evidence-based interventions for refugee resettlement.

Evidence-based interventions in refugee resettlement may be categorized into two types: (1) interventions that have shown effectiveness with refugee populations in resettlement and (2) interventions that have shown effectiveness with other populations experiencing a similar life challenge. For example, in the area of mental health, there is strong evidence from multiple systematic reviews that cognitive behavioral therapy, trauma-focused interventions, and psycho-education improve symptoms related to anxiety, depression, post-traumatic stress disorder, and/or general distress in refugee populations (Switchboard, 2022). On the other hand, in the area of financial well-being, there is strong evidence from multiple systematic reviews showing that financial capability interventions lead to numerous positive outcomes among low-income populations in general, but there is no evidence yet about these interventions with refugee populations specifically (Switchboard, 2023b). Both of these instances provide practitioners with the best available evidence for interventions for implementation (with adaptations as needed).

Although the best available evidence for a given outcome is sometimes weak or limited, nonetheless, the knowledge base about what works or is likely to work, and service providers’ access to this knowledge, continue to increase. However, knowledge about the implementation of these interventions is scant, and implementation research has been identified as an important priority for the humanitarian field (Massazza et al., 2022).

Implementation research aims to identify effective strategies for increasing the adoption, implementation, and sustainability of evidence-based interventions (Powell et al., 2015; Waltz et al., 2015). Implementation strategies may be classified into nine categories: using evaluative and iterative feedback processes; adapting and tailoring evidence-based interventions to the context, training and educating stakeholders, engaging consumers; changing organizational infrastructure; providing interactive assistance; developing stakeholder interrelationships; supporting practitioners; and utilizing financial strategies (Waltz et al., 2015). All these implementation strategies are applied in the resettlement context; for example, adapting and tailoring interventions are critical in resettlement since the evidence-based interventions must be culturally relevant (Naseh et al., 2019; Taylor et al., 2022).

Implementation research focuses on implementation outcomes, which are distinct from service outcomes or clinical outcomes (Proctor et al., 2011). Implementation outcomes include the acceptability of the evidence-based intervention to clients and providers; adoption of the evidence-based intervention by providers; appropriateness of the evidence-based intervention for clients and providers; costs, feasibility, and fidelity of the evidence-based intervention; and the evidence-based intervention’s penetration (integration into a service setting) and sustainability (Proctor et al., 2011). Again, all of these outcomes are relevant to the resettlement context. For example, western mainstream mental health interventions are often not acceptable to refugee clients due to cultural beliefs and pragmatic considerations (American Psychiatric Association, 2020).

In the pursuit of strategies to achieve these outcomes, implementation research must identify barriers to implementation. Frequently reported barriers in the implementation science literature include resource limitations and organizational culture (Bach-Mortensen et al., 2018). These are common challenges in the resettlement context (Darrow, 2015).

Successful implementation of evidence-based programs is critical to achieving client outcomes and yet is rarely monitored and evaluated in the resettlement context. Improving understanding of what effective implementation looks like, how to measure it, the strategies to achieve it, and the barriers to implementation of evidence-based practices in the resettlement context, can help inform program theories of change, the resources dedicated to ensuring effective implementation, and what is monitored and evaluated.

Because there is no comprehensive understanding of implementation research and practice in refugee resettlement, this study undertook a rapid scoping review to obtain an overview of the issue. Scoping reviews examine the extent, variety, and type of evidence on a topic area, summarize findings, and identify research gaps in the existing literature (Tricco et al., 2018). Unlike systematic reviews, scoping reviews are not intended to synthesize effectiveness data, assess risk of bias, or characterize strength of evidence (Munn et al., 2018; Tricco et al., 2018). A scoping review was deemed appropriate in light of the emerging nature of this research and the aim of mapping the underpinning key concepts to ultimately identify research gaps and implementation practice implications.

A rapid scoping review aims to balance methodological rigor with resource constraints by streamlining the traditional scoping review process (King et al., 2022). Rapid reviews are conducted within six months and typical streamlining methods include restricting the literature search in terms of dates and language; limiting the number of databases searched; using one reviewer for study selection and data extraction; and using descriptive synthesis (Haby et al., 2016; King et al., 2022). The present review was rapid due to the timeliness of the subject and resource constraints coupled with the aims of transparency, replicability, and adherence to standardized reporting standards (Featherstone et al., 2015).

Specifically, this rapid scoping review addressed the following objectives:

  1. 1.

    Identify the characteristics of implementation research in refugee resettlement, such as implementation strategies, outcomes, and research methods.

  2. 2.

    Identify commonly reported implementation barriers.

Method

This rapid scoping review was conducted following the methodological and reporting guidelines of the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR; Tricco et al., 2018). All screening, data extraction, analysis, and synthesis were conducted solely by the author. The literature search was originally conducted in May 2022 and updated in May 2023, using PubMed, PsycInfo, ASSIA, and Google Scholar. Search terms were derived from the Implementation Outcomes Framework (Proctor et al., 2011), which identifies the following outcomes and synonymous terms: acceptability, adoption, appropriateness, costs, feasibility, fidelity, penetration, and sustainability. Study titles and abstracts were searched using the following string:

refugee AND (acceptability OR adoption OR appropriate* OR feasib* OR fidelity OR implementation OR cost OR penetration OR sustainability OR satisfaction OR credib* OR uptake OR utilization OR intention OR relevance OR “perceived fit” OR compatib* OR suitab* OR practicab* OR “actual fit” OR utility OR adherence OR integrity OR maintenance OR continuation OR durab* OR incorporation OR institutionalization OR sustained OR routiniz*).

Inclusion criteria were studies conducted in the countries that resettled the vast majority of refugees from 2008 to 2023 (i.e., Australia, Canada, Finland, France, Germany, Netherlands, New Zealand, Norway, Sweden, United Kingdom, USA; Refugee Council of Australia, 2023). Studies were limited to those published from 2018 to 2023. The search was limited to resettlement countries, recognizing that resettlement is a distinct context and process apart from other stages of the refugee journey (e.g., escape, transit). The term “refugee” as used here refers to forced migrants living in resettlement countries (i.e., refugees, asylees, and asylum-seekers). No language limitations were placed on study inclusion under the assumption (based on prior experience) that if necessary, Google Translate would suffice for the purposes of this review.

Exclusion criteria were studies that did not implement an evidence-based intervention, did not describe the implementation process, and did not evaluate any implementation outcome. An evidence-based intervention was broadly defined as a practice, program, or policy that has prior demonstrated effectiveness in a population and setting (Walker et al., 2022). The prior population and setting demonstrating effectiveness were not limited to refugee resettlement because most interventions implemented with refugees must be adapted from existing evidence-based interventions originally developed for other populations and settings (Naseh et al., 2020; Taylor et al., 2022). However, the studies selected in this review must have implemented the evidence-based intervention with refugees and evaluated an implementation outcome.

For included studies, data were extracted from the full text on the following variables: country of resettlement, practice setting, occupation(s) of practitioners, number of practitioners, client outcome area, intervention, implementation outcome(s), measurement(s) of implementation outcomes, implementation strategy(ies), implementation results, research design, whether or not the study was a hybrid trial (examining both effectiveness and implementation outcomes), and implementation barriers. Implementation outcomes were specified by the taxonomy developed by Proctor et al. (2011): acceptability, adoption, appropriateness, costs, feasibility, fidelity, penetration, and sustainability. Implementation strategies were classified using the nine categories developed by the Expert Recommendations for Implementing Change panel (Waltz et al., 2015): use evaluative and iterative strategies, adapt and tailor to context, train and educate stakeholders, engage consumers, change infrastructure, provide interactive assistance, develop stakeholder interrelationships, support practitioners, and utilize financial strategies. Implementation results were categorized as having a desired effect, undesired effect, or inconclusive effect, based on the stated conclusions of each study’s author(s). Coding classifications for all other variables were developed inductively from the data in the articles. The extracted data were entered directly into an Excel spreadsheet, which includes a detailed data dictionary (please see supplemental material). To address the research objectives, the extracted data were analyzed by frequency statistics and narratively synthesized.

Results

The search yielded over 2000 records, of which 53 were ultimately included in the review (Fig. 1). Translation to English was found unnecessary at all stages of the review. The extracted characteristics of the studies are summarized in Table 1 (“Appendix 1”) and described below. The unaggregated extracted data are available in the supplemental material.

Fig. 1
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PRISMA flow diagram

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Characteristics of Setting

The USA was the most frequently represented resettlement country, constituting 34% of the 53 studies. Six additional countries accounted for another 54% of the studies. Although the search was not limited by client outcome areas, all the studies that were ultimately included using the inclusion/exclusion criteria focused on physical and mental health. Seventy percent of the studies concerned client mental or behavioral health outcomes, such as trauma symptoms or parenting skills. The remaining 30% concerned physical health outcomes, primarily health literacy.

The most frequent interventions were physical health education/promotion (21%), trauma-focused therapies (13%), and parenting interventions (11%). Health education/promotion typically entailed cultural and linguistic adaptation of video or print materials on topics such as nutrition (Bull et al., 2018; McElrone et al., 2020, 2021), physical activity (Montague & Haith‐Cooper, 2021), and maternal health (Bartlett & Boyle, 2022; Fuller et al., 2021). Trauma-focused therapies included, among others, narrative exposure therapy (de la Rie et al., 2020; Said & King, 2020; ter Heide et al., 2021); culturally modified cognitive processing therapy (Bernardi et al., 2019), and group therapy (Elswick et al., 2022; Haefner et al., 2019). Parenting interventions entailed structured programs such as the Positive Parenting Program (Arif & Van Ommen, 2021) and GenerationPMTO (Ballard et al., 2018).

The remaining interventions were diverse, such as care coordination/integration (e.g., Chua et al., 2022); mindfulness (e.g., Blignault et al., 2021); family strengthening interventions (Betancourt et al., 2020; Van Es et al., 2021); and latent tuberculosis management (Pépin et al., 2022). Some interventions were at the institutional level, such as the aforementioned care coordination/integration or educating healthcare providers about refugees’ health insurance eligibility with the aim of increasing healthcare access (Leps et al., 2022). For complete intervention details, please see the supplemental materials.

About two-thirds (62%) of the interventions took place in resettlement agencies and physical and/or mental health clinics, and eight interventions took place online. For example, Lindegaard et al. (2022) examined the feasibility of internet-based cognitive behavioral therapy for Afghan refugee youth, and Röhr et al. (2021) examined the cost of a self-help app for Syrian refugees. Over 40% of the practitioners in the studies were mental health therapists. Peer facilitators and interpreters working in collaboration with other providers were represented in another one-third of all studies.

Objective 1: Characteristics of Implementation

More than 40% of the studies did not specify the number of practitioners implementing the interventions. Among those that did, all but four studies reported fewer than 20 practitioners, with about half of those having five or fewer practitioners. Three studies involved large numbers of practitioners. Bleile et al. (2021) engaged 190 trained volunteer facilitators in a movement-based psychosocial intervention for children in refugee reception centers in the Netherlands. Ford-Paz et al. (2022) trained 948 community stakeholders working with refugees in trauma-informed care and psychological first aid. The largest study was a survey of 2753 physicians in Canada about their utilization of a refugee health insurance program (Leps et al., 2022).

Acceptability was the most studied implementation outcome, examined in 77% of the studies. Feasibility was studied in over one-half of the studies. About one-third of the studies examined appropriateness and one-fifth, fidelity. The remaining implementation outcomes—adoption, cost, sustainability, and penetration—were examined in relatively few of the studies. The most common methods of measuring implementation outcomes were client retention rate, semi-structured interviews with clients and providers, client satisfaction scales, and client focus groups. Regarding the measurement of specific implementation outcomes, acceptability and feasibility were most frequently measured by client retention rates and semi-structured client interviews. Adoption was measured by provider surveys and client uptake rates. Appropriateness was most commonly measured using semi-structured interviews with clients and/or providers. Cost and penetration were measured primarily using administrative data. Fidelity was most frequently assessed using intervention checklists. Finally, sustainability was measured using semi-structured interviews with providers (please see supplemental file).

No measurement instruments, methods, or interpretations were used uniformly across the studies. For example, semi-structured interviews, used in nearly half the studies, were tailored to each context. Client satisfaction was measured ten different ways in ten studies, five of which used self-developed questionnaires. Client retention rates were variously operationalized as completion of all intervention sessions, percentage of sessions attended, or completion of post-tests, and there was no objective standard about what constitutes an acceptable retention rate.

The most frequently used implementation strategy was adapting/tailoring the EBP intervention to the context (70% of studies). The remaining implementation strategies were reported rarely in the studies. Most adaptations were cultural, linguistic, and trauma-informed. For example, GenerationPMTO, a manualized, evidence-based parenting intervention, was adapted for Karen refugees in the USA to address cultural background, trauma history, and resettlement stress (Ballard et al., 2018). A few adaptations were technological. For example, ter Heide et al. (2021) reported on refugee clients’ use of videoconferencing therapy during the COVID-19 pandemic. Training/educating stakeholders was employed in one-third of the studies, and evaluative/iterative strategies in one-fifth. For example, Bentley et al. (2021) implemented a train-the-trainers model for “Islamic Trauma Healing,” an intervention that integrated evidence-based trauma-focused cognitive behavioral therapy principles with cultural and religious practices. As an example of evaluative/iterative strategies, Orenstein et al. (2019) described a multi-step process of developing clinical decision support for health care of newly arrived refugees, including needs assessment, task analysis, pre-implementation testing, local implementation, staged dissemination, and feedback.

Research designs were primarily mixed methods, one-group pretest–posttest, or qualitative. There were only four randomized controlled trials. One-half of the studies were hybrid implementation-effectiveness trials. For example, Haefner et al. (2019) implemented a group therapy program originally designed for veterans with post-traumatic stress disorder, with refugees diagnosed with the same condition. Using a one-group mixed methods design, they examined both reported improvement in clients’ symptoms (effectiveness outcome) as well as providers’ satisfaction with the intervention (implementation outcome).

Many of the studies examined multiple outcomes. For example, acceptability and feasibility were often measured together. Additionally, authors often used multiple measures for one outcome. For example, in one study, acceptability was measured by client retention rate and a provider acceptability survey (Sigmarsdóttir et al., 2023). Because of such multiple measures and multiple outcomes, a total of 109 implementation results were tracked by the 53 studies (see supplemental material). Overall, desirable implementation results were reported for 78% of the implementation outcomes, undesirable results for 15%, and inconclusive results for 7%. Desirable implementation rates by outcome were: 76% of 41 acceptability outcomes, 84% of 31 feasibility outcomes, 76% of 17 appropriateness outcomes, 67% of 9 fidelity outcomes, 67% of 6 adoption outcomes, 67% of 3 cost outcomes, 100% of 1 sustainability outcome, and 100% of 1 penetration outcome. Table 2 (“Appendix 2”) provides examples of desirable, undesirable, and inconclusive implementation results to illustrate the variety of implementation research aims, methods, and outcomes.

Objective 2: Implementation Barriers

Of the 53 articles, 25 described barriers encountered during the implementation process. The most frequently mentioned barriers were lack of staff time (35% of 25 studies), budget constraints (35%), workflow disruption (22%), scheduling conflicts (22%), and limited availability of interpreters (17%). This constellation of implementation barriers was vividly described in one study that implemented culturally-adapted group visits as part of a program to improve primary care for Bhutanese refugee children in the USA (Bull et al., 2018):

Several challenges arose during the course of the project. Our clinic lacks capacity to run more than one-group visit at a time due to personnel and space constraints. The group visits were only possible with the assistance of an in‑person interpreter, which may pose a barrier for replication in other clinics. In addition, a significant amount of time was required to recruit and remind patients of the group visits, prepare for the visit, review charts beforehand, and conduct individual examinations during the group visit. There was a high no‑show rate for the first visit. It was calculated at our clinic that we needed to have at least eight patients in order to make the group visits cost‑effective. Low numbers of patients from other linguistic/ethnic groups made group visits for other linguistic/ethnic groups impractical regarding the time and cost involved (p. 1329).

Other barriers included lack of provider knowledge, COVID-19 restrictions, technological problems, staff turnover, staff feeling helpless, and balancing intervention fidelity with contextual adaptations. There was no evident relationship between the intervention implemented and the barriers encountered, indicating that the identified barriers are cross-cutting.

Discussion

This rapid scoping review has provided an overview of implementation research in refugee resettlement, including its characteristics and barriers to implementation. Fifty-three studies published from 2018 to 2023 were identified for inclusion, and data were extracted on implementation variables. These findings are used to identify gaps in implementation research and implications for implementation practice.

All the studies concerned the implementation of physical or mental health interventions. This reveals a gap in implementation research in other important refugee outcome areas such as economic well-being and community belonging. The results further show a gap in implementation research on case management/social service interventions, which are a major element of resettlement assistance (Shaw & Funk, 2019; UNHCR, n.d.). As well, there is a gap in implementation research on creating more welcoming communities for refugees, despite the availability of evidence-based interventions that help to achieve this outcome (Switchboard, 2021). Overall, the present findings echo those of a systematic review which concluded that “research on refugee services reflects the failure to attend to all aspects of service provision” (Subramanian et al., 2022, p. 1).

Only about one-third (37%) of the studies included peer facilitators and/or interpreters as practitioners. Amid calls for greater engagement of refugee communities in research (Deps et al., 2022; Hearn et al., 2022; Kia-Keating & Juang, 2022), these results suggest that future implementation research should include more interpreters and peer facilitators as collaborators throughout all stages of the research process to shed further light on their roles, challenges, and effects in implementation. Engaging these community members in this manner will increase community empowerment, enhance trust, generate novel insights from diverse perspectives, and illuminate pathways of care.

Acceptability and feasibility were the most frequently studied implementation outcomes. These are generally assessed in the early to middle stages of the implementation process (Proctor et al., 2011). In contrast, implementation outcomes typically assessed later in the process—adoption, cost, sustainability, and penetration—were rare in these studies. While this may be a function of time, with later-stage research still forthcoming, it is notable that there was no set of studies that followed an implementation project through all its stages. Thus it appears that these are one-off studies rather than part of longer-term, comprehensive implementation plans. This short-term, fragmented approach impedes knowledge-building. Future implementation plans should encompass all implementation stages to maximize impact.

The findings of this study bear implications for implementation research methods. Most of the studies were naturalistic, using mixed methods, one-group pretest–posttest, or qualitative research designs. Randomized controlled trials (RCTs) were rare (8% of the studies). There are many challenges to conducting RCTs with refugees (Cohen & Yaeger, 2021). Services often cannot be withheld from refugee clients for ethical or programmatic reasons. Refugees may be reluctant or even retraumatized because randomization reminds them of the process of obtaining asylum or resettlement, which they perceive as a matter of chance with few winners (Rondung et al., 2022). Randomization can potentially fracture refugee communities if their members perceive that some receive more benefits or better services than others in the same circumstances. Thus, rather than pursuing the RCT gold standard, implementation researchers in refugee resettlement should explore possibilities for using quasi-experimental designs to enhance research rigor in this field. Such designs may include natural experiments (e.g., Jaschke & Kosyakova, 2021), nonequivalent comparison group designs (e.g., Robertson et al., 2019), and interrupted time-series designs (e.g., Yelland et al., 2020). These methods provide improved internal validity beyond the oft-employed one-group pretest–posttest design, while avoiding the problems associated with randomization. Furthermore, hybrid trials such as the many included in this review provide an efficient means to simultaneously evaluate both the implementation and effectiveness of cultural adaptations of existing evidence-based interventions. Additionally, further attention is needed to assess organizational readiness for change and how this influences the selection of intervention strategies and impacts implementation outcomes (Kerns et al., 2023).

Studies were highly idiosyncratic in their measurement approaches, frequently using self-developed instruments. This is reflective of the larger implementation research field, where it has been argued that “the observed practice of one-time use of non-validated measures should be reduced, although it can probably not completely be avoided. In implementation science, measures often need to be tailored to target groups and settings, which implies that validated measures may be lacking. If validated measures are available, however, the reason for designing a new measure needs to be particularly convincing” (Wensing, 2021, p. 3). The most frequently used implementation outcome measure was client retention rate, which varied widely from 20 to 100%. Yet, there was no consensus about an acceptable rate. However, one of the included studies, a meta-analysis of dropout rates from mental health interventions for refugees, found an average dropout rate of 19%, similar to non-refugee populations (Semmlinger et al., 2021). Like the present study, Semmlinger et al. (2021) also found wide variation in definitions of dropout. They recommended that a duration- or dose-based operationalization of dropout be used. Therefore, it is proposed here that a retention rate of approximately 80% be considered the threshold for “acceptable” retention. Such a uniform cutoff would be consistent with a “common elements” approach to intervention research (Engell et al., 2023).

Finally, any consideration of implementation science in refugee resettlement must address the lack of organizational capacity, as evidenced by the identified budget and staffing barriers. It is well-established, for example, that the US resettlement program is severely underfunded (Brown & Scribner, 2014; Fee, 2019; Hanna, 2011), thus limiting organizational capacity to conduct implementation research and practice. In this vein, it is noteworthy that none of the studies examined the influence of the larger socio-economic-political environment, including organizational leadership and culture, well-known factors affecting implementation (Bauer et al., 2015). Future research on these influences in resettlement implementation research and practice is imperative to gain a fuller understanding of this multisystemic context.

Limitations

This rapid scoping review has several limitations. Consistent with the nature of rapid reviews, only published academic research articles were accessed; the search was limited to publications between 2018 and 2023. Moreover, a sole reviewer conducted the study selection and data extraction; this may have introduced bias in study selection, data extraction, and interpretation. A larger review team would allow any discrepancies to be resolved by consensus, thereby potentially reducing bias. Additionally, this study is limited to the resettlement context and is not generalizable to other refugee settings such as camps. Further, this study examined implementation barriers but not facilitators. As such, this study is exploratory and is intended to open future pathways for more rigorous implementation research and application in this area.

Conclusion

This study is the first to assess the landscape of implementation research in refugee resettlement. This is a nascent field with potential for improving service quality and client outcomes for this vulnerable population. Several suggestions for improvement of implementation research have been made. To effectively and efficiently help forcibly displaced people build new lives, all stakeholders—funders, donors, resettlement agencies, physical and mental health providers, and refugee communities—must collaborate to enhance the implementation of evidence-based practice in refugee resettlement.