Sensitivity and specificity of clinical trials. Randomized v historical controls

Abstract

The relative accuracy of randomized control trials (RCT) and historical control trials (HCT) in determining effective [human] therapies has not been compared since there is no external verification of efficacy. Six therapies studied by both methods were reviewed. Most HCT concluded therapy was better than control but few RCT agreed. Sensitivity and specificity were calculated for each type of trial by combining published results with all possible combinations of effectiveness. The sensitivity of HCT was 0.80-1.00 (mean, 0.90) and specificity was 0.0-0.27 (mean, 0.11). The sensitivity of RCT was 0.0-0.27 (mean, 0.12) and specificity was 0.67-1.00 (mean, 0.88). Defects of RCT are more easily corrected than those of HCT. Trial design and the probability of errors should be considered when deciding how much credence to give to a clinical trial.