New Research

Health and Access to Care during the First 2 Years of the ACA Medicaid Expansions


with Laura Wherry, The New England Journal of Medicine. 376: 947-956.

BACKGROUND By September 2015, a total of 29 states and Washington, D.C., were participating in Medicaid expansions under the Affordable Care Act. We examined whether Medicaid expansions were associated with changes in insurance coverage, health care use, and health among low-income adults. METHODS We compared changes in outcomes during the 2 years after implementation of the Medicaid expansion (2014 and 2015) relative to the 4 years before expansion (2010 through 2013) in states with and without expansions, using data from the National Health Interview Survey. The sample consisted of 60,766 U.S. citizens who were 19 to 64 years of age and had incomes below 138% of the federal poverty level. Outcomes included insurance coverage, access to and use of medical care in the past 12 months, and health status as reported by the respondents. RESULTS A total of 29 states and Washington, D.C., expanded Medicaid by September 1, 2015. In year 2 after implementation, uninsurance rates were reduced in expansion states relative to nonexpansion states (difference-in-differences estimate, -8.2 percentage points; P<0.001) and rates of Medicaid coverage were increased (difference-in-differences estimate, 15.6 percentage points; P<0.001). Expansions were not associated with significant changes in the likelihood of a doctor visit or overnight hospital stay or health status as reported by the respondent. However, as compared with nonexpansion states, expansion states had a decrease in reports of inability to afford needed follow-up care (difference-in-differences estimate, -3.4 percentage points; P=0.002) and in reports of worry about paying medical bills (difference-in-differences estimate, -7.9 percentage points; P=0.002) and an increase in reports of medical care being delayed because of wait times for appointments (difference-in-differences estimate, 2.6 percentage points; P=0.02). CONCLUSIONS Medicaid expansion was associated with increased insurance coverage and access to care during the second year of implementation, but it was also associated with longer wait times for appointments, which suggests that challenges in access to care persist

Press Coverage: Vox

The Effect of the Patient Protection and Affordable Care Act Medicaid Expansions on Financial Well-Being


with Luojia Hu, Robert Kaestner, Bhashkar Mazumder, and Ashley Wong revise and resubmit, Journal of Public Economics

We examine the effect of the Medicaid expansions under the 2010 Patient Protection and Affordable Care Act (ACA) on financial outcomes using credit report data for a large sample of individuals. We employ the synthetic control method (Abadie et al., 2010) to compare individuals living in states that expanded Medicaid to those that did not. We find that the Medicaid expansions significantly reduced the number of unpaid bills and the amount of debt sent to third-party collection agencies among those residing in zip codes with the highest share of low income, uninsured individuals. Our estimates imply a reduction in collection balances of around $600 to $1,000 among those who gain Medicaid coverage due to the ACA. Our findings suggest that the ACA Medicaid expansions had important financial impacts beyond health care use.

Press Coverage: NY Times Upshot, Washington Post Wonkblog, Pacific Standard, International Business Times, NY Mag, NPR


Drug Firms' Payments and Physicians' Prescribing Behavior in Medicare Part D


with Colleen Carey and Ethan Lieber

In a pervasive but controversial practice, drug firms frequently make monetary or in-kind payments to medical providers. Critics are concerned that drug firms are distorting prescribing behavior away from the best interests of patients, while defenders of the practice claim that payments arise from the need to educate providers about changing drug technologies. Using two different identification strategies, we investigate the effect of payments from drug firms on individual-level prescribing behavior in Medicare Part D. We find that individuals whose providers receive payments from a drug firm tend to increase expenditure on the firm's products. Our method accounts for the selection of physicians into payments (which may result if, e.g., pharmaceutical firms target payments to physicians who see a large number of patients) and our finding holds even when we look over time within individuals who change providers. However, using hand-collected efficacy data on four major therapeutic classes, we find that those receiving payments also prescribe higher-quality drugs on average. In addition, we examine four case studies of major drugs going off patent. Providers receiving payments from the firms experiencing the patent expiry transition their patients just as quickly to generics as prescribers who do not receive such payments. These results suggest that, absent other interventions to facilitate education, policies such as the Physician Payments Sunshine Act may reduce the efficacy of drugs prescribed.

The Long-Term Effects of Early Life Medicaid Coverage


with Laura Wherry revise and resubmit, Journal of Human Resources

Although the link between the fetal environment and later life health and achievement is well-established, few studies have evaluated the extent to which public policies aimed at improving fetal health can generate benefits that persist into adulthood. In this study, we evaluate how a rapid expansion of prenatal and child health insurance through the Medicaid program affected adult outcomes of individuals born between 1979 and 1993 who gained access to coverage in utero and as children. We find that those whose mothers gained eligibility for prenatal coverage under Medicaid have lower rates of obesity as adults and fewer hospitalizations related to endocrine, nutritional and metabolic diseases, and immunity disorders as adults, with particularly pronounced reductions in visits associated with diabetes and obesity. We also find that the prenatal expansions improved educational and economic outcomes for affected cohorts. Cohorts who gained Medicaid eligibility in utero have higher high school graduation rates and we find evidence suggesting that they have higher incomes in adulthood. We find effects of public eligibility in other periods of childhood on self-reported health, hospitalizations, and income later in life, but these effects are smaller in magnitude. Our results indicate that expanding Medicaid prenatal coverage had sizeable long-term benefits for the next generation.

Press Coverage: Vox
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