Adjusting for attrition in school-based samples - Bias, precision, and cost trade-offs of three methods

Attrition in longitudinal studies can introduce nonresponse bias when estimating parameters. Methods to correct for nonresponse include survey-based approaches (tracking) as well as analytically based, methods (weighting, sample selection modeling). Using data from a multiwave school-based study of adolescents, substance use estimates are compared across methods. Methods are validated by simulating effects of attrition at baseline, and the relative efficiency of each approach with respect to a known ''gold standard'' is calculated Results indicate that weighting may provide sufficient adjustment for nonresponse in other similar studies. Sample selection modeling requires assumptions that are not met in this setting, and severe bias results. The high casts associated with full tracking efforts may be avoidable, as hem we find that tracking vias apr inefficient approach for bias reduction.