Observational data and clinical trials: narrowing the gap?
Allen
A
Wilcox
Sholom
S
Wacholder
D002318:Cardiovascular Diseases / Q000517:prevention & control*; D002986:Clinical Trials as Topic; D015331:Cohort Studies; D015914:Estrogen Replacement Therapy / Q000009:adverse effects*; D005260:Female; D006306:Health Surveys; D006801:Humans; D019370:Observation