Patterns and predictors of physician adoption of new cardiovascular drugs

Background: Little is known about physicians' approaches to adopting new cardiovascular drugs and how adoption varies between drugs of differing novelty. Methods: Using data on dispensed prescriptions from IMS Health's Xponent (TM) database, we created a cohort of all primary care physicians (PCPs) and cardiologists in Pennsylvania who regularly prescribed anticoagulants, antihypertensives and statins from 2007 to 2011. We examined prescribing of three new cardiovascular drugs of differing novelty: dabigatran, aliskiren and pitavastatin. Outcomes were rapid adoption of each new drug, defined by early and sustained monthly prescribing detected by group-based trajectory models, by physicians within the first 15 months of marketplace introduction. Results: 5953 physicians regularly prescribed each drug class. The majority of physicians (63.8%) adopted zero new drugs in the first 15 months, 35.0% rapidly adopted one or two, and 1.2% rapidly adopted all three. Physicians were more likely to rapidly adopt the most novel drug, dabigatran (27.3%), than aliskiren (10.5%) or pitavastatin (8.0%). Physician specialty and sex were the most consistent predictors of adoption. Compared to PCPs, cardiologists were more likely to rapidly adopt dabigatran (Adjusted Odds Ratio 8.90, 95% confidence interval 7.42-10.67; P < 0.001) aliskerin (2.05, CI 1.56-2.69; P < 0.001) and pitavastatin (3.44, CI 2.60-4.57; P < 0.001). Female physicians were less likely to adopt dabigatran (0.71, CI 0.59-0.85; P < 0.001) and aliskiren (0.64, CI 0.49-0.83; P < 0.001). Conclusions: Physicians vary in their prescribing of recently-introduced cardiovascular drugs. Though most physicians did not rapidly adopt any new cardiovascular drugs, drug novelty and cardiology training were associated with greater adoption.