Web-Based Program Exposure and Retention in the Families Improving Together for Weight Loss Trial.

BACKGROUND: Interventions that incorporate behavioral skills training and parental involvement have been effective for promoting weight loss among middle and upper class youth; however, few studies have produced similar weight loss effects in underserved ethnic minority youth. PURPOSE: This study examined whether online program exposure (in both an online tailored intervention and an online health education comparison program) predicted greater retention among African American youth and their parents in the Families Improving Together (FIT) for Weight Loss trial. METHODS: Parent-adolescent dyads (N = 125) were randomized to either an online tailored intervention program (n = 63) or an online health education comparison program (n = 62). Paradata including login data were used to determine the number of sessions viewed (0-8) and the number of minutes spent online per session. Study retention, defined as collection of adolescent anthropometric measures at 6 months postintervention, was the outcome. RESULTS: Logistic regression analyses showed a significant effect for login rate on retention (OR = 1.21, 95% CI [1.04, 1.39]). Total number of sessions viewed, child age, child sex, parent age, and parent sex accounted for 11% of the variance in retention at 6 months post- intervention. Participants who were retained spent a significantly greater number of minutes during each session (M = 12.99, SD = 11.63) than participants who were not retained (M = 7.77, SD = 11.19), t(123) = 2.24, p = .027, d = 0.45. CONCLUSIONS: The use of paradata from online interventions is a novel and feasible approach for examining exposure in web-based interventions and program retention in underserved ethnic minority families. TRIAL REGISTRATION: ClinicalTrials.gov NCT01796067. Registered January 23, 2013.