Bellerose, M., Collin, L., Daw, J. (2022). The ACA Medicaid expansion and perinatal insurance, health care use, and health outcomes: a systematic review. Health Affairs. 41(1).
In this systematic review of 24 studies published between January 2014 and April 2021, we found that the Affordable Care Act (ACA) state Medicaid expansions increased preconception and postpartum Medicaid coverage with corresponding declines in uninsurance, private insurance coverage, and insurance churn. We found limited evidence that Medicaid expansion increased perinatal health care use or improved infant birth outcomes overall, although some studies reported reduced racial and ethnic disparities in rates of prenatal and postpartum visit attendance, maternal mortality, low birthweight, and preterm births.
This paper was cited in the 2025 Economic Report of the President
Bellerose, M., Daw, J., Steenland, M.W. (2023). Differences in self-reported and billed postpartum visits among Medicaid-insured individuals. JAMA Network Open. 6(12).
In this cross-sectional study using South Carolina Medicaid claims data linked to Pregnancy Risk Assessment Monitoring System (PRAMS) survey responses, we found that estimates of postpartum visit use derived from Medicaid claims undercount postpartum visit receipt by systematically missing care received by unqualified immigrants with Emergency Medicaid for delivery and those who transition to private insurance during the postpartum period. Accounting for postpartum insurance transitions when conducting studies using Medicaid claims data may improve estimates of postpartum health care use and outcomes.
Bellerose, M., James, O., Shroff, J., Ryan, A., Meyers, D. (2025). Combining patient survey data with diagnosis codes improved Medicare Advantage risk-adjustment accuracy. Health Affairs. 44(1).
Under the current Medicare Advantage (MA) risk-adjustment system, plans are incentivized to "upcode," or report diagnosis codes on enrollees’ medical claims reflecting additional and more severe health conditions to increase enrollees’ risk scores and corresponding plan payments. In this study, we used national 2016-2019 medical and pharmaceutical claims linked to Consumer Assessment of Healthcare Providers and Systems (CAHPS) survey responses from 151,432 MA enrollees to test four alternative methods of contructing risk scores that are less susceptible to upcoding. We found that relative to currently used models, models combining diagnosis codes with survey responses were more predictive of health care use, suggesting that survey responses could be used in tandem with diagnosis codes to improve the integrity and performance of MA risk adjustment.
Steenland, M.W., Fabi, R.E., Bellerose, M., Desir, A., White, M.S, Wherry, L. (2023). JAMA. 330(3).
Bellerose, M., Rodriguez. M., Vivier, P.M. (2022). Health Services Research. 57(1).