Dropout From Psychological Interventions for Pathological Health Anxiety: A Three-Level Meta-Analysis of Randomized Controlled Trials

This study aimed to provide the first comprehensive evidence on the prevalence and predictors of dropout in psychological interventions for pathological health anxiety. A database search in Web of Science, EMBASE, PubMed, Scopus, PsycINFO and the Cochrane Central Register of Controlled Trials identified 28 eligible randomized controlled trials (40 intervention conditions; 1783 participants in the intervention condition), published up to 18 June 2024. Three-level meta-analytic results showed a weighted average dropout rate of 9.67% (95% confidence interval [CI] [6.49%, 14.17%]), with dropout equally likely from treatment and control conditions (odds ratio = 1.07, 95% CI [0.80, 1.44]). Moderator analyses indicated no statistically significant effects of study, participant, treatment or therapist characteristics, except for the country of study. These findings suggest that the average dropout rate is relatively low compared with those reported for other mental health conditions and highlight the importance of considering cultural and societal factors when evaluating treatment adherence. Future research should continue to explore the complex and multifaceted factors influencing dropout to improve the design and implementation of psychological interventions for pathological health anxiety.