T. Kiriazova1,2,3, D.M. Cheng1, S.M. Coleman1, E. Blokhina4, E. Krupitsky4,5, M.C. Lira2, C. Bridden2, A. Raj6, J.H. Samet1,2. 1Boston University, United States; 2Boston Medical Center, United States; 3Future Without AIDS Foundation, Ukraine; 4First St. Petersburg Pavlov State Medical University, Russia; 5St. Petersburg Bekhterev Research Psychoneurological Institute, Russia; 6University of California, San Diego, United States
Background: Participant attrition in longitudinal studies may introduce bias and diminish research quality. Awareness of participant characteristics predictive of attrition is limited in Eastern Europe. The study aimed to identify factors associated with attrition among HIV-infected risky drinkers from an HIV prevention trial in St. Petersburg, Russia. We examined whether current injection drug use (IDU), binge drinking, depression, HIV non-disclosure, stigma and lifetime history of incarceration were predictors of attrition. We also explored effect modification due to gender. Methods: The HERMITAGE trial had planned assessments at baseline, 6 and 12 months. Complete loss to follow-up (LTFU), defined as no follow-up visits after baseline, was the primary outcome, and the secondary outcome, time to first missed visit, was defined as the time from baseline to first missed visit (6 or 12 months), with censoring at end of study or death. We used multiple logistic regression models for the primary analysis, and Cox proportional hazards models for the secondary analysis. Results: Of 660 participants, 101 (15.3%) had no follow-up. No significant associations between independent variables and complete LTFU were observed. In secondary analysis, current IDU (AHR 1.39, 95% CI 1.03, 1.87) and HIV non-disclosure (AHR 1.38, 95% CI 1.03, 1.86) were significantly associated with missing a follow-up visit. Gender stratified analyses suggested a larger impact of binge drinking among males and incarceration history among females for missing a follow-up visit. Conclusion: Current IDU and HIV non-disclosure were significantly associated with a missed follow-up visit among HIV-infected Russian risky drinkers. Understanding predictors of attrition may inform efforts to improve participant retention in research studies.