title: Competing risks bias arising from an omitted risk factor.
abstract: The authors describe a form of selection bias that may arise when a second disease selectively removes from the population persons susceptible to the primary disease of interest. Two examples of this bias are given: 1) a lack of association between an exposure and the primary disease may appear as an inverse association, and 2) a direct association between exposure and primary disease may be greatly attenuated. These examples of bias require the presence of an unknown risk factor in addition to the exposure of interest.
authors.affiliation: Division of Cancer Prevention and Control, National Cancer Institute, Bethesda, MD 20892-4200.
authors.forename: A
authors.initials: A
authors.lastname: Schatzkin
authors.forename: E
authors.initials: E
authors.lastname: Slud
mesh_terms: D002784:Cholesterol / Q000097:blood; D015331:Cohort Studies; D003327:Coronary Disease / Q000097:blood / Q000401:mortality; D004812:Epidemiologic Methods; D006801:Humans; D009369:Neoplasms / Q000097:blood / Q000401:mortality; D012107:Research Design; D012306:Risk; D012307:Risk Factors
chemical_list: D002784:Cholesterol