Is pharmaceutical detailing informative? Evidence from contraindicated drug prescriptions

Crestor, an important but controversial cholesterol-lowering drug, is contraindicated for use by senior and Asian patients. In this paper, we exploit this fact along with unique physician-level prescription and detailing data for statin drugs to examine the hypothesis that detailing is informative. Our tests are based on a simple model in which detailing impacts physicians' expected match utility of Crestor for different types of patients. We find strong evidence for the informative-detailing hypothesis: relative to the other patients, detailing significantly reduces physicians' likelihood of prescribing Crestor to contraindicated patients. Our results are robust to detailing being correlated with physician-specific unobserved factors and/or differential trends in individual physicians' attitudes toward Crestor.