title: Clinical epidemiological research in lower-income countries faces specific methodological challenges.
authors.forename: J André
authors.initials: JA
authors.lastname: Knottnerus
authors.forename: Peter
authors.initials: P
authors.lastname: Tugwell
mesh_terms: D003625:Data Collection / Q000379:methods*; D003906:Developing Countries; D015340:Epidemiologic Research Design; D006801:Humans; D011203:Poverty