Sample sizes for prevention trials have been too small.
Planners of several large prevention trials have overestimated the expected incidence of events in the control group, largely because they failed either to recognize or to adequately correct for various effects of population selection.
Consequently, the studies have been too small in size or too short in duration to achieve their stated objectives.
The selection effects include those engendered by the choice of the target population, the self-selection of volunteers, and protocol exclusions.
This paper presents a taxonomy of these effects and the likely direction of their influence on the incidence of events and on mortality rates from other causes.
Little information is available to help sample size planners in adjusting for these effects.
Mots-clés Pascal : Epidémiologie, Essai clinique, Echantillonnage, Méthodologie, Biais méthodologique, Prévention, Homme, Etats Unis, Amérique du Nord, Amérique, Incidence
Mots-clés Pascal anglais : Epidemiology, Clinical trial, Sampling, Methodology, Methodological bias, Prevention, Human, United States, North America, America, Incidence
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 93-0499724
Code Inist : 002B30A01A1. Création : 199406.