A Systematic Review Investigating the Nonparticipation Rate and Recruitment Challenges in Yoga Trials for Addictive Disorders

Abstract Background: Yoga has been studied as an effective alternative therapy for substance use disorders, demonstrating its ability to reduce stress and addictive behaviors while improving self-control and self-esteem. However, not everyone may be willing or able to engage in yoga for various reasons. Furthermore, there is a lack of systematic reviews and meta-analyses of the existing research on this topic. Objective: The objective is to explore the nonparticipation rate in yoga intervention randomized controlled trials related to addictive disorders, and to explore the reasons for nonparticipation in yoga trials related to addictive disorders. Methods: We searched Google Scholar, CENTRAL, and PubMed for peer-reviewed published RCTs that incorporated yoga interventions in any format of at least one session. Data were extracted using standard procedures, and the risk of bias was evaluated. Pooled analysis and sensitivity analysis were done. Results: About 54% of potential participants were not included. The pooled effect size was 0.544 (95% confidence interval: 0.301–0.787), with an I ² = 99.797. Key barriers included failure to meet inclusion criteria, such as medical conditions, mental health issues, and specific health conditions such as posttraumatic stress disorder, depression, and heart disease. Participant refusals and lack of interest in randomization or the study itself were common reasons for nonparticipation. Scheduling conflicts were also frequently reported as a significant obstacle. Two broad categories for noninclusion were meeting exclusion criteria, and not interested/declined to participate. Conclusion: Understanding reasons for noninclusion can lead to more efficient and effective recruitment efforts in future trials and also possibly guide the design of future studies to minimize dropout rates and ensure a representative sample.