A Quasi-Experimental Study of Medicaid Expansion and Urban Mortality in the American Northeast.

To investigate the association of state-level Medicaid expansion and non-elderly mortality rates from 1999 to 2018 in Northeastern urban settings. This quasi-experimental study utilized a synthetic control method to assess the association of Medicaid expansion on non-elderly urban mortality rates [1999-2018]. Counties encompassing the largest cities in the Northeastern Megalopolis (Washington D.C., Baltimore, Philadelphia, New York City, and Boston) were selected as treatment units ( = 5 cities, 3,543,302 individuals in 2018). Cities in states without Medicaid expansion were utilized as control units ( = 17 cities, 12,713,768 individuals in 2018). Across all cities, there was a significant reduction in the neoplasm (Population-Adjusted Average Treatment Effect = -1.37 [95% CI -2.73, -0.42]) and all-cause (Population-Adjusted Average Treatment Effect = -2.57 [95%CI -8.46, -0.58]) mortality rate. Washington D.C. encountered the largest reductions in mortality (Average Treatment Effect on All-Cause Medical Mortality = -5.40 monthly deaths per 100,000 individuals [95% CI -12.50, -3.34], -18.84% [95% CI -43.64%, -11.67%] reduction, = < 0.001; Average Treatment Effect on Neoplasm Mortality = -1.95 monthly deaths per 100,000 individuals [95% CI -3.04, -0.98], -21.88% [95% CI -34.10%, -10.99%] reduction, = 0.002). Reductions in all-cause medical mortality and neoplasm mortality rates were similarly observed in other cities. Significant reductions in urban mortality rates were associated with Medicaid expansion. Our study suggests that Medicaid expansion saved lives in the observed urban settings.