The 3D-Transition study : objectives, methods, and implementation of an innovative planned missing data design

Abstract

The prevalence of mental health problems represents a significant burden on school and community health resources as early as preschool. Reducing this burden requires a better understanding of the developmental mechanisms linking children’s early vulnerabilities with mental health after the transition to formal schooling. The 3D-Transition study (2017-2021; ClinicalTrials.org ID: NCT04873518) follows 939 participants from a pregnancy cohort in Québec (Canada) as they transition to kindergarten and first grade to examine these mechanisms. Biannual assessments include questionnaires from two parents as well as teachers, parent-child observations, anthropometric measurements, and age-sensitive cognitive assessments. Salivary cortisol is also collected on 11 days over a 16-month period in a subsample of 384 participants to examine possible changes in child salivary cortisol levels across the school transition, and their role in difficulties observed during the transition. A combination of planned missing data designs is implemented to reduce participant burden, where incomplete data is collected without introducing bias after the use of multiple imputation. The 3D-Transition study will contribute to an evidence-based developmental framework of child mental health from pregnancy to school age. In turn, this framework can help inform prevention programs delivered in health care settings during pregnancy, childcare centers, preschools, and schools.