Returns to scientific publications for pharmaceutical products in the United States.

Drug-specific clinical and health economic and outcomes research (HEOR) publications have amassed, but their effect on drug sales is largely unknown. We estimated the impact of publications on pharmaceutical sales in 3 markets (statins, rheumatoid arthritis, and asthma drugs) with varying generic competition. An event-study approach with fixed effects and difference-in-fixed-effects modeling was used to estimate the causal effects of drug-specific publications on subsequent quarter's drug-specific sales and volume. High-impact clinical and HEOR publications have significant positive effects on sales (mediated through price) and volume in the statin market (high generic competition). High-impact clinical publications have a significant positive effect on sales (mediated through volume) in low-generic competition market (asthma). The effects of publications in the rheumatoid arthritis market (no generic competition) on sales were null. Manufacturers' investment in clinical and HEOR publications needs to be strategic and should be anticipated and complemented by public investments in such studies.