title: What makes large epidemiological studies comparable?
authors.forename: I
authors.initials: I
authors.lastname: Cerveri
authors.forename: R
authors.initials: R
authors.lastname: De Marco
mesh_terms: D003430:Cross-Sectional Studies; D003625:Data Collection; D004812:Epidemiologic Methods; D006306:Health Surveys; D006801:Humans; D008171:Lung Diseases / Q000453:epidemiology* / Q000628:therapy; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology* / Q000628:therapy; D015272:Pulmonary Medicine / Q000379:methods*; D015203:Reproducibility of Results; D012107:Research Design