Predicting Later Study Withdrawal in Participants Active in a Longitudinal Birth Cohort Study for 1 Year: The TEDDY Study.

OBJECTIVE : To identify predictors of later study withdrawal among participants active in The Environmental Determinants of Diabetes in the Young (TEDDY) for 1 year. METHODS : Multiple logistic regression was used to discriminate 3,042 children active in TEDDY for the first 3 years from 432 children who withdrew in Years 2 or 3. Predictor variables were tested in blocks-demographic, maternal lifestyle behaviors, stress and child illness, maternal reactions to child's increased diabetes risk, in-study behaviors-and a final best model developed. RESULTS : Few demographic factors predicted study withdrawal. Maternal lifestyle behaviors, accuracy of the mother's risk perception, and in-study behaviors were more important. Frequent child illnesses were associated with greater study retention. CONCLUSIONS : Demographic measures are insufficient predictors of later study withdrawal among those active in a study for at least 1 year; behavioral/psychological factors offer improved prediction and guidance for the development of retention strategies.