Choosing cases and controls: the clinical epidemiology of "clinical investigation".
Feinstein
A R
AR
Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510.
Horwitz
R I
RI
D002985:Clinical Protocols; D002986:Clinical Trials as Topic / Q000379:methods*; D004812:Epidemiologic Methods; D006801:Humans; D012107:Research Design