Titre : | Illustrating bias due to conditioning on a collider. (2010) |
Auteurs : | Stephen-R COLE ; HAITAO CHU (.) : USA. Department of Biostatistics. Unc Gillings School of Global Public Health. Chapel Hill. NC. ; PLATT (Robert-W) : CAN. Department of Biostatistics. McGill University. Montreal. ; Charles POOLE ; David RICHARDSON ; SCHISTERMAN (Enrique-F) : USA. Epidemiology Branch. Eunice Kennedy Shriver Nichd. Nih. Bethesda. MD. ; Daniel Westreich ; Department of Epidemiology. Unc Gillings School of Global Public Health. Chapel Hill. NC. USA |
Type de document : | Article |
Dans : | International journal of epidemiology (vol. 39, n° 2, 2010) |
Pagination : | 417-420 |
Langues: | Anglais |
Mots-clés : | Conditionnement ; Sélection ; Méthodologie ; Méthode ; Epidémiologie ; Biais |
Résumé : | [BDSP. Notice produite par INIST-CNRS JF8D8R0x. Diffusion soumise à autorisation]. That conditioning on a common effect of exposure and outcome may cause selection, or collider-stratification, bias is not intuitive. We provide two hypothetical examples to convey concepts underlying bias due to conditioning on a collider. In the first example, fever is a common effect of influenza and consumption of a tainted egg-salad sandwich. In the second example, case-status is a common effect of a genotype and an environmental factor. In both examples, conditioning on the common effect imparts an association between two otherwise independent variables ; we call this selection bias. |