New Research

Early Coverage, Access, Utilization, and Health Effects of the Affordable Care Act Medicaid Expansions: A Quasi-Experimental Study

with Laura Wherry, forthcoming Annals of Internal Medicine

Background: In 2014, only 26 states and D.C. chose to implement the Affordable Care Act (ACA) Medicaid expansions for low-income adults. Objective: To estimate whether the state Medicaid expansions were associated with changes in insurance coverage, access to and utilization of health care, and self-reported health. Design: Comparison of outcomes before and after the expansions in states that did and did not expand Medicaid. Setting: U.S. Participants: Citizens aged 19-64 with family incomes below 138% of the Federal Poverty Level in the 2010-2014 National Health Interview Surveys. Measurements: Health insurance coverage (private, Medicaid, uninsured); health insurance better than last year; visits with doctors in general practice and with specialists; hospitalizations and ED visits; skipped or delayed medical care; usual source of care; diagnoses of diabetes, high cholesterol, and hypertension; self-reported health; and depression. Results: In the second half of 2014, low-income adults in expansion states experienced increased health insurance (7.4 percentage points; 95% CI, -11.3 to -3.4) and Medicaid (10.5 percentage points; 95% CI, 6.5 to 14.5) coverage, and increased quality of insurance coverage compared to a year ago (7.1 percentage points; 95% CI, 2.7 to 11.5) when compared to adults in states that did not expand Medicaid. Medicaid expansions were associated with increased visits with doctors in general practice (6.6 percentage points; 95% CI, 1.3 to 12.0), overnight hospital stays (2.4 percentage points; 95% CI, 0.7 to 4.2), and rates of diagnosis of diabetes (5.2 percentage points; 95% CI, 2.4 to 8.1) and high cholesterol (5.7 percentage points; 95% CI, 2.0 to 9.4); changes in other outcomes were not statistically significant. Limitations: Observational study may be susceptible to unmeasured confounders; relies on self-reported data; limited post-ACA timeframe provides information on short-term changes only. Conclusions: The ACA Medicaid expansions were associated with higher rates of insurance coverage, improved quality of coverage, increased utilization of some types of health care, and higher rates of diagnosis of chronic health conditions for low-income adults.

Press Coverage: CBS, Philadelphia Inquirer, NYT Upshot

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

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.

Childhood Medicaid Coverage and Later Life Health Care Utilization

with Laura Wherry, Robert Kaestner, Bruce D. Meyer

Policy-makers have argued that providing public health insurance coverage to the uninsured lowers long-run costs by reducing the need for expensive hospitalizations and emergency department visits later in life. In this paper, we provide evidence for such a phenomenon by exploiting a legislated discontinuity in the cumulative number of years a child is eligible for Medicaid based on date of birth. We find that having more years of Medicaid eligibility in childhood is associated with fewer hospitalizations and emergency department visits in adulthood for blacks. Our effects are particularly pronounced for hospitalizations and emergency department visits related to chronic illnesses and those of patients living in low-income neighborhoods. Furthermore, we find evidence suggesting that these effects are larger in states where the difference in the number of Medicaid-eligible years across the cutoff birthdate is greater. Calculations suggest that lower rates of hospitalizations and emergency department visits during one year in adulthood offset between 3 and 5 percent of the initial costs of expanding Medicaid.

Press Coverage: FiveThirtyEight, NY Times, NBER Digest, Washington Post Wonkblog, NYTimes Upshot

The Long-Term Effects of Early Life Medicaid Coverage

with Laura Wherry

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