Abstract
Background/aimsTo assess pre- and postnatal factors associated with participation in a randomized clinical trial of daily docosahexaenoic supplementation in toddlers born preterm. We hypothesized that enrolled families would not differ from those who did not participate.MethodChildren eligible for the Omega Tots trial were born at <35 completed weeks' gestation and were 10-16 months of age at recruitment. Eligibility data abstracted from the medical record were linked with the child's birth certificate. The primary outcome was whether the family enrolled, declined, or was non-responsive to recruitment efforts. Log-binomial regression calculated risk ratios (RR).Results316 families enrolled, 1089 declined, and 1081 were non-responsive. Enrolling, rather than not enrolling, was negatively associated with caregivers being married (RR = 0.76, 95% CI: 0.62, 0.94), identifying as White (RR = 0.76, 95% CI: 0.60, 0.94), and children being born at later gestational ages (RR1-week = 0.96, 95% CI: 0.92, 0.99); positively associated with children weighing <1500 g at birth (RR = 1.26, 95% CI: 1.01, 1.55), attending a neonatology specialty clinic (RR = 1.46, 95% CI: 1.19, 1.80), family participation in WIC (RR = 1.39, 95% CI: 1.13, 1.72), and living in an urban zip code (RR = 1.68, 95% CI: 1.30, 2.17). Varied associations with enrolling rather than declining, enrolling rather than being non-responsive, and declining rather than being non-responsive were identified.ConclusionsMaternal, child, and socioeconomic characteristics were different for families who enrolled, relative to families who did not enroll. Factors associated with enrollment differed between families who were non-responsive to recruitment attempts and those who declined enrollment, with additional differences identified between families who declined participation and those who were non-responsive. Recruitment initiatives tailored to ensuring enrollees reflect the source population may improve generalizability.