title: Subgroup analyses: primary and secondary.
authors.forename: A S
authors.initials: AS
authors.lastname: Detsky
authors.forename: I G
authors.initials: IG
authors.lastname: Naglie
mesh_terms: D000367:Age Factors; D003627:Data Interpretation, Statistical; D006801:Humans; D018579:Patient Selection; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data*