Associations between Medicaid expansion and nurse staffing ratios and hospital readmissions

To examine the associations between Medicaid expansion and nurse staffing ratios and hospital-wide readmission rates.

Secondary data from the 2011-2016 Healthcare Cost Report Information System, the American Hospital Association Annual Survey, and the Hospital Compare data.

Difference-in-difference models are used to compare outcomes in hospitals located in states that expanded Medicaid with those located in nonexpansion states. The changes in nurse staffing ratios and hospital-wide readmission rates are calculated in each one of the postexpansion years (2014, 2015, and 2016), compared to pre-expansion.

Results indicate that nurse staffing ratios increased, whereas hospital-wide readmission rates declined in expansion states relative to nonexpansion states. Nurse staffing ratios increased by 0.33, 0.42, and 0.46 registered nurses hours per adjusted patient days in 2014, 2015, and 2016 in hospitals located in expansion states, compared with hospitals in nonexpansion states after expansion. This increase was statistically significant (P < .001) in 2015 and 2016, but marginally significant (P = .016) in 2014. Hospital-wide readmission rates statistically significantly decreased by 9, 16, and 18 per 10 000 patients (P < .001) in 2014, 2015, and 2016, respectively, in expansion vs nonexpansion states hospitals after expansion.

Medicaid expansion was associated with gradually improved hospitals' nurse staffing ratios and hospital-wide readmission rates from 2014 through 2016. The continued monitoring of quality measures of hospitals can help assess the impact of Medicaid expansion over a longer period of time.