HIV / STI
Lost But Not Forgotten—An Analysis of Factors Associated with Loss to Follow-Up in a Randomized Controlled Trial Kara Herrera* Kara Herrera Mark S. Dworkin
Background: Ethnic minorities and youth are priority populations for HIV-related health interventions but are more likely to be lost to follow-up (LTFU) in randomized controlled trials (RCTs). Given RCTs provide the highest level of evidence to establish causal associations in clinical research and attrition can undermine study finding validity, understanding LTFU is essential. Therefore, we determined factors associated with LTFU among young Black men who have sex with men (BMSM).
Methods: We recruited young (18-34 years) HIV-positive BMSM throughout the United States for an RCT of an iteratively developed avatar mobile app intervention designed to promote antiretroviral adherence vs. an avatar app attention control focused on food safety. Enrollment coincided with COVID-19 stay-at-home orders. Participants were randomized in a 1:1 ratio to the intervention or attention control app and followed for 6-months. Logistic regression using backward model selection were employed to determine factors associated with LTFU.
Results: One-quarter (26.5%) of 253 young BMSM were LTFU at the 6-month follow-up. For each point increase in the Multidimensional Scale of Perceived Social Support, the prevalence of LTFU was 0.86 times as likely (PR: 0.86; 95% CI: 0.76-0.97). Additionally, those randomized to the attention control arm had over two-fold increased prevalence of LTFU compared to those randomized to the intervention (PR: 2.48; 95% CI:1.06-5.79).
Discussion: This is the first analysis investigating factors associated with LTFU in an RCT among HIV-positive BMSM. High LTFU was observed and was associated with randomization to the control arm and lower self-perceived social support. Future studies of young BMSM should consider developing an attention control as engaging as the intervention to minimize LTFU. Additionally, determining the prevalence of lower self-perceived social support during RCT approach development might be considered to obtain accurate sample size estimates.