title: Representativeness is not helpful in studying heterogeneity of effects across subgroups.
authors.affiliation: RTI Health Solutions, Research Triangle Park, NC, USA, Boston University School of Public Health, Boston, MA, USA and Cardiff University School of Medicine, Cardiff, UK.
authors.forename: Kj
authors.initials: K
authors.lastname: Rothman
authors.forename: Ee
authors.initials: E
authors.lastname: Hatch
authors.forename: Jej
authors.initials: J
authors.lastname: Gallacher
mesh_terms: D016021:Epidemiologic Studies; D012494:Sampling Studies