title: Methodological issues in the measurement of substance use.
authors.affiliation: Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pennsylvania 15213.
authors.forename: N L
authors.initials: NL
authors.lastname: Day
authors.forename: N
authors.initials: N
authors.lastname: Robles
mesh_terms: D000428:Alcohol Drinking / Q000706:statistics & numerical data*; D003625:Data Collection; D005260:Female; D006801:Humans; D008385:Marijuana Smoking / Q000453:epidemiology*; D011247:Pregnancy