Long-Term Care Pharmacy Market Shares and Differences in Skilled Nursing Facilities Served.

Medications and pharmacy services are critical to post-acute care (PAC) in skilled nursing facilities (SNFs), yet little is known about the long-term care (LTC) pharmacies that provide them. We estimated the market shares of LTC pharmacies and how SNFs differed between pharmacies. This cross-sectional study used data from SNFs that provided PAC services in Rhode Island (RI) in 2019. We applied the parametric g-formula to compare SNF pharmacy-related deficiencies and medication use measures between LTC pharmacies while standardizing for SNF membership in a chain and number of beds. Among 75 SNFs, 68 (91%) were served by either Omnicare ( n  = 32, 43%) or PharMerica ( n  = 36, 48%), and 7 (9%) by other LTC pharmacies. After covariate adjustment, PharMerica SNFs had the lowest prevalences of any pharmacy-related deficiency (PharMerica, 63.2%; Omnicare, 80.2%; other LTC pharmacy, 69.1%) and antianxiety medication use (PharMerica, 9.7%; Omnicare, 13.6%; other LTC pharmacy, 13.5%), but estimates were imprecise. The RI market is highly concentrated between LTC pharmacies. If similarly high LTC pharmacy market concentration exists nationally, there is enormous promise for efficiently delivering interventions to improve medication management in SNFs. However, it may also present a risk of harm if policies do not maintain sufficient competition and innovation is stifled.