Random error (misclassification) in exposure measurements usually biases a relative risk, regression coefficient, or other effect measure towards the null value (no association).
The most important exception is Berkson type error, which causes little or no bias.
Berkson type error arises, in particular, due to use of group average exposure in place of individual values.
Random error in exposure measurements, Berkson or otherwise, reduces the power of a study, making it more likely that real associations are not detected.
Random error in confounding variables compromises the control of their effect, leaving residual confounding.
Random error in a variable that modifies the effect of exposure on health-for example, an indicator of susceptibility-tends to diminish the observed modification of effect, but error in the exposure can create a spurious appearance of modification.
Methods are available to correct for bias (but not generally power loss) due to measurement error, if information on the magnitude and type of error is available.
These methods can be complicated to use, however, and should be used cautiously as « correction » can magnify confounding if it is present.
Mots-clés Pascal : Méthode étude, Erreur mesure, Biais méthodologique, Exposition professionnelle, Epidémiologie, Correction erreur, Erreur aléatoire, Etude statistique, Homme
Mots-clés Pascal anglais : Investigation method, Measurement error, Methodological bias, Occupational exposure, Epidemiology, Error correction, Random error, Statistical study, Human
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0503818
Code Inist : 002B30B02C. Création : 19/02/1999.