| Titre : | Effects of Adjusting for Instrumental Variables on Bias and Precision of Effect Estimates. (2011) |
| Auteurs : | Jessica-A MYERS ; Joshua-J GAGNE ; Robert-J GLYNN ; Krista-F HUYBRECHTS ; JOFFE (Marshall-M) : USA. Department of Biostatistics and Epidemiology. School of Medicine. University of Pennsylvania. Philadelphia. PA. ; Jeremy-A RASSEN ; ROTHMAN (Kenneth-J) : USA. Rti Health Solutions. Research Triangle Park. North Carolina. ; Sebastian SCHNEEWEISS |
| Type de document : | Article |
| Dans : | American journal of epidemiology (vol. 174, n° 11, 2011) |
| Pagination : | 1213-1222 |
| Langues: | Anglais |
| Mots-clés : | Biais ; Estimation ; Epidémiologie ; Simulation ; Sélection |
| Résumé : | [BDSP. Notice produite par INIST-CNRS pGH8JR0x. Diffusion soumise à autorisation]. Recent theoretical studies have shown that conditioning on an instrumental variable (IV), a variable that is associated with exposure but not associated with outcome except through exposure, can increase both bias and variance of exposure effect estimates. Although these findings have obvious implications in cases of known IVs, their meaning remains unclear in the more common scenario where investigators are uncertain whether a measured covariate meets the criteria for an IV or rather a confounder. The authors present results from two simulation studies designed to provide insight into the problem of conditioning on potential IVs in routine epidemiologic practice. The simulations explored the effects of conditioning on IVs, near-IVs (predictors of exposure that are weakly associated with outcome), and confounders on the bias and variance of a binary exposure effect estimate. The results indicate that effect estimates which are conditional on a perfect IV or near-IV may have larger bias and variance than the unconditional estimate. However, in most scenarios considered, the increases in error due to conditioning were small compared with the total estimation error. In these cases, minimizing unmeasured confounding should be the priority when selecting variables for adjustment, even at the risk of conditioning on IVs. |
Service Documentation EHESP
Me connecter
PORTAIL DOCUMENTAIRE
École des hautes études en santé publique
Catalogue
Multi-bases
Accueil
Sélection de la langue
Adresse
Service Documentation EHESPBibliothèque Rennes Avenue du Professeur Léon Bernard – CS 74312 – 35043 Rennes Cedex Bibliothèque MSSH Paris 20 avenue George Sand - 93210 La Plaine Saint-Denis
France
Bibliothèque Rennes : 02 99 02 29 50 Bibliothèque MSSH Paris : 02 99 02 24 50
contact