Personal Formularies of Primary Care Physicians Across 4 Health Care Systems

Abstract

Key Points Question Given the potential quality and safety benefits associated with a more limited and conservative list of drugs a physician prescribes, how does the personal formulary size and use of core drugs vary among primary care physicians at 4 large health care organizations? Findings In this retrospective cohort study of 4655 primary care physicians, 9\u2009496\u2009766 new prescriptions were written during a 2-year period, and for the 4 institutions, the mean personal formulary size ranged from 150 to 296. Multivariable modeling showed that personal formulary size was significantly associated with panel size, number of encounters, and physician’s sex. Meaning This study found wide variations in physicians’ personal formularies, suggesting potential opportunities for improving physician practices associated with recommendations for more conservative prescribing.