A systematic review of recruitment and retention of ethnic minorities and migrants in obesity prevention randomised controlled trials

Background Participants' recruitment and retention into community-based interventions can be challenging, especially in research involving ethnic minorities and migrants. Despite known challenges, there are limited reviews that probe recruitment and retention strategies involving ethnic minorities and migrants in the Organisation for Economic Cooperation and Development (OECD) countries. This systematic review aimed to measure recruitment and retention rates and identify the barriers and facilitators to effective recruitment and retention of ethnic minorities and migrants in community-based obesity prevention Randomised Control Trials (RCTs) in OECD countries.Methods This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Five databases (CINAHL, Cochrane, Embase, Medline and PsychInfo) were searched from January 2000 to March 2022, in addition to Google and Google Scholar. Methodological quality and risk of bias were assessed, and pooled analysis and meta-ethnographic analysis were conducted on the included studies.Results Twenty-five studies were included in the review. The pooled analysis found a 64% rate of recruitment of ethnic minorities in RCTs, with a retention rate of 71%. Key facilitators identified were-use of multiple communication channels, incentives, recruiting community champions, participant convenience and employing culturally sensitive strategies. Key barriers to participation were limited access to study sites, time constraints, limited trust, perceived fear, and anxiety.Conclusion Findings suggest the importance of undertaking culturally appropriate recruitment and retention strategies to minimise barriers and facilitate effective recruitment and retention of low-income ethnic minorities and migrants in community-based research.