Author Affiliations: Departments of Medicine, Epidemiology, and Health Services, Cardiovascular Health Research Unit, University of Washington, Seattle (Dr Psaty); and Institute for Health Policy Studies, University of California, San Francisco, and Deputy Editor, JAMA, Chicago, Ill (Dr Rennie).
In this issue of THE JOURNAL, Black and colleagues1 report
the results of an aborted clinical trial. In the Controlled Onset Verapamil
Investigation of Cardiovascular End Points (CONVINCE) study, a large randomized
double-blind equivalence trial with many strengths, the investigators compared
a controlled-onset extended-release formulation of the calcium channel blocker
verapamil with standard therapies (atenolol or hydrochlorothiazide) for hypertension.
Randomization was stratified on type of standard care—diuretics or β-blockers—with
the result that there were, in effect, 2 parallel trials within CONVINCE,
verapamil vs each of the other 2. When the rates of withdrawal from treatment
were noted to be higher than expected, the sample size was increased from
15 000 to 16 600 with a new target of 2246 primary events, which
included first myocardial infarction, stroke, or cardiovascular disease–related
Psaty BM, Rennie D. Stopping Medical Research to Save MoneyA Broken Pact With Researchers and Patients. JAMA. 2003;289(16):2128-2131. doi:10.1001/jama.289.16.2128