Association of 340B contract pharmacy growth with county-level characteristics.

To estimate the association of 340B contract pharmacy growth between 2009 and 2019 with county-level characteristics, including availability of health care providers, health care spending, population, and socioeconomic characteristics. Observational study. We constructed county-level maps of 340B contract pharmacy penetration for the years 2009 and 2019 by 340B participant type (hospital or safety-net clinic). We then used a multivariable linear probability regression model to estimate the association of county-level characteristics in 2009 with the probability of gaining at least one 340B contract pharmacy within the county by 2019. We estimated separate regressions for safety-net clinics and hospitals. We find that growth of contracts with 340B hospitals was uncorrelated with uninsured rates, poverty rates, or areas of medical underservice. By contrast, we find that growth of contracts with 340B safety-net clinics was positively correlated with poverty rates and metropolitan statistical status. These findings suggest different patterns of access for patients. Our results add systematic evidence of a difference in how the 2 main types of 340B participants-hospitals and safety-net clinics-use the 340B program. Policy proposals to reform 340B should consider reforms for safety-net clinics and hospitals separately.