Source:http://linkedlifedata.com/resource/pubmed/id/2923129
General Info
Affiliation
Division of Cancer Prevention and Control, National Cancer Institute, Bethesda, MD 20892-4200.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.
PMID
2923129