Validity of self-reports of alcohol and other drug use: A multitrait-multimethod assessment.

Used 4 methods (self-reported rating, self-reported intake, peer-reported rating, and peer-reported intake) and multiple analytical criteria to assess the construct validity of reports of 3 types of substance use (alcohol, marihuana, and cigarettes) in a study of 194 college students who were members of friendship pairs. Ss answered questions about their own use and their friend's use of substances, classified their own and their friend's use of each substance according to 6 categories, and completed scales measuring the negative consequences of marihuana and alcohol. The resulting multitrait-multimethod matrix was analyzed in the traditional fashion as well as with confirmatory factor analysis. Convergent and discriminant validity for the 3 substance use traits were quite adequate, although the validity of the peer-reported intake measure of alcohol use may be considered inadequate according to some criteria. Results demonstrate the usefulness of multimethod assessment and confirmatory factor analysis for research on construct validity and for derivation of more accurate measures of drug use. (47 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)