title: Making comparisons.
authors.affiliation: Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia 19104.
authors.forename: J A
authors.initials: JA
authors.lastname: Grisso
mesh_terms: D016022:Case-Control Studies; D002986:Clinical Trials as Topic; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D006801:Humans; D008499:Medical Records; D012107:Research Design; D013223:Statistics as Topic