Reasons for participation in a child development study: Are cases with developmental diagnoses different from controls?

Background: Current knowledge about parental reasons for allowing child participation in research comes mainly from clinical trials. Fewer data exist on parents' motivations to enrol children in observational studies.

Objectives: Describe reasons parents of preschoolers gave for participating in the Study to Explore Early Development (SEED), a US multi-site study of autism spectrum disorder (ASD) and other developmental delays or disorders (DD), and explore reasons given by child diagnostic and behavioural characteristics at enrolment.

Methods: We included families of children, age 2-5 years, participating in SEED (n = 5696) during 2007-2016. We assigned children to groups based on characteristics at enrolment: previously diagnosed ASD; suspected ASD; non-ASD DD; and population controls (POP). During a study interview, we asked parents their reasons for participating. Two coders independently coded responses and resolved discrepancies via consensus. We fit binary mixed-effects models to evaluate associations of each reason with group and demographics, using POP as reference.

Results: Participants gave 1-5 reasons for participation (mean = 1.7, SD = 0.7). Altruism (48.3%), ASD research interest (47.4%) and perceived personal benefit (26.9%) were most common. Two novel reasons were knowing someone outside the household with the study conditions (peripheral relationship; 14.1%) and desire to contribute to a specified result (1.4%). Odds of reporting interest in ASD research were higher among diagnosed ASD participants (odds ratio [OR] 2.89, 95% confidence interval [CI] 2.49-3.35). Perceived personal benefit had higher odds among diagnosed (OR 1.92, 95% CI 1.61-2.29) or suspected ASD (OR 3.67, 95% CI 2.99-4.50) and non-ASD DD (OR 1.80, 95% CI 1.50-2.16) participants. Peripheral relationship with ASD/DD had lower odds among all case groups.

Conclusions: We identified meaningful differences between groups in parent-reported reasons for participation. Differences demonstrate an opportunity for future studies to tailor recruitment materials and increase the perceived benefit for specific prospective participants.