SUMMARY

Abstract

In prevention studies, it is often of interest to investigate the incidence of initial drug experimentation or other drug use milestones and their relationship to individual attributes such as the level of parental monitoring or rebelliousness. Thus survival analysis is the methodology of choice. Survival analysis methods deal e ciently with data from individuals who leave the study prematurely and do not return. However often individuals do return to the study. The application of survival analysis to a situa-tion in which individuals miss assessments and later return is nonstandard. This paper examines the use of multiple imputation as a methodology for utilizing information from assessments following a missed assessment