Predicting Attrition in a Pediatric Asthma Intervention Study

OBJECTIVES: To operationalize a comprehensive description of attrition, including pre-inclusion, dropout, and attrition due to intermittent missing data, and to test a predictive model of attrition using a data set from a randomized controlled intervention in pediatric asthma. METHODS: Participants included children, ages 4-12, diagnosed with asthma and their caregivers. Demographic variables and outcome measures of asthma morbidity were examined in 327 families to determine their association with attrition. RESULTS: Families who did not complete randomization and the intervention tended to have younger caregivers than did completers. Caregiver age emerged as the most consistent predictor of pre-inclusion and dropout attrition. There were no significant predictors of attrition due to intermittent missing data. CONCLUSION: Younger caregivers may be at particular risk for attrition in pediatric asthma intervention studies and warrant special attention by investigators.