The quest for "power" : Contradictory hypotheses and inflated sample sizes.
To have the power'of avoiding undersized clinical trials, the customary statistical strategy used in the past few decades is aimed at rejecting both a null stochastic hypothesis and a contradictory alternative hypothesis.
This approach gives a trial the « power'to confirm the »insignificance'of differences much smaller than the large value of delta desired in trials done to show efficacy, In many instances, however, a prime problem is that the current double-significance'approach produces sample sizes 2-3 times larger than needed for stochastic confirmation of large differences (=delta).
The inflated sample sizes and consequent problems can be avoided if a realistic value for delta is chosen and maintained thereafter, and if an adequate « capacity'is calculated for » single significance. .
Mots-clés Pascal : Essai clinique, Analyse statistique, Taille échantillon, Epidémiologie, Méthodologie, Evaluation, Homme
Mots-clés Pascal anglais : Clinical trial, Statistical analysis, Sample size, Epidemiology, Methodology, Evaluation, Human
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0454077
Code Inist : 002B30A01A1. Création : 25/01/1999.