Primary care competition and quality of care: Empirical evidence from Medicare.

In this paper, we explore the effects of primary care physician (PCP) practice competition on five distinct quality metrics directly tied to screening, follow-up care, and prescribing behavior under Medicare Part B and D. Controlling for physician, practice, and area characteristics as well as zip code fixed effects, we find strong evidence that PCP practices in more concentrated areas provide lower quality of care. More specifically, PCPs in more concentrated areas are less likely to perform screening and follow-up care for high blood pressure, unhealthy bodyweight, and tobacco use. They are also less likely to document current medications. Furthermore, PCPs in more concentrated areas have a higher amount of opioid prescriptions as a fraction of total prescriptions.