The Environmental Determinants of Diabetes in the Young (TEDDY) study: predictors of early study withdrawal among participants with no family history of type 1 diabetes.

OBJECTIVE The Environmental Determinants of Diabetes in the Young (TEDDY) study seeks to identify environmental triggers of autoimmunity and type 1 diabetes mellitus (T1DM) in children at increased human-leukocyte-antigen conferred genetic risk for this disease. The objective of this study was to identify predictors of early withdrawal from TEDDY among families with no immediate family history of T1DM. METHOD Logistic multiple regression was used to discriminate 2994 (83%) families currently active in the TEDDY study for ≥1 yr from 763 (17%) families who withdrew in the first year. Data collected on the screening form at the time of the child's birth and from interview and questionnaire data obtained at the baby's first study visit (at ≤4.5 months of age) were used. RESULTS Significant and independent predictors of early withdrawal included country of residence, young maternal age, no father participation, and female gender of the study participant. Mothers of children who withdrew were more likely to report smoking during pregnancy, abstaining from alcohol, and reducing their work hours or not working at all during pregnancy. Mothers who withdrew were also more likely to underestimate their child's risk for T1DM and fail to respond to multiple items on the enrollment questionnaires or interview. Among mothers with accurate risk perceptions, those experiencing high anxiety about their child's risk were more likely to be early withdrawals. CONCLUSIONS Identifying families at high risk for study withdrawal at the time of enrollment allows for targeting these families with individually tailored plans to help maintain their participation in the study.