HIV among immigrants living in high-income countries: A realist review of evidence to guide targeted approaches to behavioural HIV prevention

Background: Immigrants from developing and middle-income countries are an emerging priority in HIV prevention in high-income countries. This may be explained in part by accelerating international migration and population mobility. However, it may also be due to the vulnerabilities of immigrants including social exclusion along with socioeconomic, cultural and language barriers to HIV prevention. Contemporary thinking on effective HIV prevention stresses the need for targeted approaches that adapt HIV prevention interventions according to the cultural context and population being addressed. This review of evidence sought to generate insights into targeted approaches in this emerging area of HIV prevention.Methods: We undertook a realist review to answer the research question: 'How are HIV prevention interventions in high-income countries adapted to suit immigrants' needs?' A key goal was to uncover underlying theories or mechanisms operating in behavioural HIV prevention interventions with immigrants, to uncover explanations as how and why they work (or not) for particular groups in particular contexts, and thus to refine the underlying theories. The realist review mapped seven initial mechanisms underlying culturally appropriate HIV prevention with immigrants. Evidence from intervention studies and qualitative studies found in systematic searches was then used to test and refine these seven mechanisms.Results: Thirty-four intervention studies and 40 qualitative studies contributed to the analysis and synthesis of evidence. The strongest evidence supported the role of 'consonance' mechanisms, indicating the pivotal need to incorporate cultural values into the intervention content. Moderate evidence was found to support the role of three other mechanisms - 'understanding', 'specificity' and 'embeddedness' - which indicated that using the language of immigrants, usually the 'mother tongue', targeting (in terms of ethnicity) and the use of settings were also critical elements in culturally appropriate HIV prevention. There was mixed evidence for the roles of 'authenticity' and 'framing' mechanisms and only partial evidence to support role of 'endorsement' mechanisms.Conclusions: This realist review contributes to the explanatory framework of behavioural HIV prevention among immigrants living in high-income countries and, in particular, builds a greater understanding of the suite of mechanisms that underpin adaptations of interventions by the cultural context and population being targeted.