More doctors, better health? A generalised synthetic control approach to estimating impacts of increasing doctors under Brazil's ' s Mais Medicos programme

Worldwide, there are an insufficient number of primary care physicians to provide accessible, high-quality primary care services. Better knowledge on the health impacts of policies aimed at improving access to primary care physicians is important for informing future policies. Using a generalised synthetic control estimator (GSC), we estimate the effect of the increase in primary care physicians from the Programa Mais Me<acute accent>dicos <acute accent> dicos in Brazil. The GSC allows us to estimates a continuous treatment effects which are heterogenous by region. We exploit the variation in physicians allocated to each Brazilian microregion to identify the impact of an increasing Mais Me<acute accent>dicos <acute accent> dicos primary care physicians. We explore hospitalisations and mortality rates (both total and from ambulatory care sensitive conditions) as outcomes. Our analysis differs from previous work by estimating the impact of the increase in physician numbers, as opposed to the overall impact of programme participation. We examine the impact on hospitalisations and mortality rates and employ a panel dataset with monthly observations of all Brazilian microregion over the period 2008-2017. We find limited effects of an increase in primary care physicians impacting health outcomes- with no significant impact of the Programa Mais Me<acute accent>dicos <acute accent> dicos on hospitalisations or mortality rates. Potential explanations include substitution of other health professionals, impacts materialising over the longer-term, and poor within- region allocation of Mais Me<acute accent>dicos <acute accent> dicos physicians.