Dosemeci et al. (Am J Epidemiol 1990 ; 132 : 746-8) gave examples in which nondifferential misclassification of exposure reversed the direction of a trend.
Gilbert (Am J Epidemiol 1991 ; 134 : 440-1) proposed that these examples occurred because the errors in exposure were systematic, and she pointed out that the relation between the measured and the true exposure was not monotonic.
Assuming that the mean response either monotonically increases or decreases with the true exposure and that the exposure misclassification is nondifferential, the authors show that if the mean value of the measured exposure increases with the true exposure, then the direction of the trend cannot be reversed.
Consequently, Gilbert's intimation that reversal of trend can only occur when errors are systematic is correct.
Mots-clés Pascal : Epidémiologie, Méthodologie, Classification, Exposition, Erreur, Méthode statistique, Biais
Mots-clés Pascal anglais : Epidemiology, Methodology, Classification, Exposure, Error, Statistical method
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 94-0684061
Code Inist : 002B30A01A1. Création : 09/06/1995.