Confounding of subgroup analyses in randomized data.
Groenwold
Rolf H H
RH
University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, PO Box 85500, 3508 GA, Utrecht, The Netherlands. r.h.h.groenwold@umcutrecht.nl
Donders
A Rogier T
AR
van der Heijden
Geert J M G
GJ
Hoes
Arno W
AW
Rovers
Maroeska M
MM
D015986:Confounding Factors, Epidemiologic; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D013223:Statistics as Topic