title: Comment on: "a simple and valid tool distinguished efficacy from effectiveness studies".
authors.forename: Mark G
authors.initials: MG
authors.lastname: Spigt
authors.forename: Daniel
authors.initials: D
authors.lastname: Kotz
mesh_terms: D006801:Humans; D016032:Randomized Controlled Trials as Topic / Q000379:methods*; D012107:Research Design; D018401:Sample Size; D013997:Time Factors; D016896:Treatment Outcome