Laura R. Wherry, PhD; Sarah Miller, PhD
Disclaimer: The findings and conclusions in this article are those of the authors and do not necessarily reflect the views of the Research Data Center, the National Center for Health Statistics, or the Centers for Disease Control and Prevention.
Acknowledgment: The authors thank Patricia Barnes and John Sullivan for their assistance in accessing the restricted-use data used in this project.
Disclosures: Authors have disclosed no conflicts of interest. Forms can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M15-2234.
Editors' Disclosures: Christine Laine, MD, MPH, Editor in Chief, reports that she has no financial relationships or interests to disclose. Darren B. Taichman, MD, PhD, Executive Deputy Editor, reports that he has no financial relationships or interests to disclose. Cynthia D. Mulrow, MD, MSc, Senior Deputy Editor, reports that she has no relationships or interests to disclose. Deborah Cotton, MD, MPH, Deputy Editor, reports that she has no financial relationships or interest to disclose. Jaya K. Rao, MD, MHS, Deputy Editor, reports that she has stock holdings/options in Eli Lilly and Pfizer. Sankey V. Williams, MD, Deputy Editor, reports that he has no financial relationships or interests to disclose. Catharine B. Stack, PhD, MS, Deputy Editor for Statistics, reports that she has stock holdings in Pfizer and Johnson & Johnson.
Reproducible Research Statement:Study protocol: Not available. Statistical code: Available from Dr. Wherry (e-mail, email@example.com). Data set: Available from the National Center for Health Statistics (www.cdc.gov/rdc/index.htm).
Requests for Single Reprints: Laura R. Wherry, PhD, Division of General Internal Medicine & Health Services Research, David Geffen School of Medicine at UCLA, 911 Broxton Avenue, Room 226, Los Angeles, CA 90024; e-mail, firstname.lastname@example.org.
Current Author Addresses: Dr. Wherry: Division of General Internal Medicine & Health Services Research, David Geffen School of Medicine at UCLA, 911 Broxton Avenue, Room 226, Los Angeles, CA 90024.
Dr. Miller: University of Michigan, Stephen M. Ross School of Business R4416, Business Economics and Public Policy, 701 Tappan Avenue, Ann Arbor, MI 48109.
Author Contributions: Conception and design: L.R. Wherry, S. Miller.
Analysis and interpretation of the data: L.R. Wherry, S. Miller.
Drafting of the article: L.R. Wherry, S. Miller.
Critical revision of the article for important intellectual content: L.R. Wherry, S. Miller.
Final approval of the article: L.R. Wherry, S. Miller.
Statistical expertise: L.R. Wherry, S. Miller.
Administrative, technical, or logistic support: S. Miller.
Collection and assembly of data: L.R. Wherry, S. Miller.
In 2014, only 26 states and the District of Columbia chose to implement the Patient Protection and Affordable Care Act (ACA) Medicaid expansions for low-income adults.
To evaluate whether the state Medicaid expansions were associated with changes in insurance coverage, access to and utilization of health care, and self-reported health.
Comparison of outcomes before and after the expansions in states that did and did not expand Medicaid.
Citizens aged 19 to 64 years with family incomes below 138% of the federal poverty level in the 2010 to 2014 National Health Interview Surveys.
Health insurance coverage (private, Medicaid, or none); improvements in coverage over the previous year; visits to physicians in general practice and specialists; hospitalizations and emergency department visits; skipped or delayed medical care; usual source of care; diagnoses of diabetes, high cholesterol, and hypertension; self-reported health; and depression.
In the second half of 2014, adults in expansion states experienced increased health insurance (7.4 percentage points [95% CI, 3.4 to 11.3 percentage points]) and Medicaid (10.5 percentage points [CI, 6.5 to 14.5 percentage points]) coverage and better coverage than 1 year before (7.1 percentage points [CI, 2.7 to 11.5 percentage points]) compared with adults in nonexpansion states. Medicaid expansions were associated with increased visits to physicians in general practice (6.6 percentage points [CI, 1.3 to 12.0 percentage points]), overnight hospital stays (2.4 percentage points [CI, 0.7 to 4.2 percentage points]), and rates of diagnosis of diabetes (5.2 percentage points [CI, 2.4 to 8.1 percentage points]) and high cholesterol (5.7 percentage points [CI, 2.0 to 9.4 percentage points]). Changes in other outcomes were not statistically significant.
Observational study may be susceptible to unmeasured confounders; reliance on self-reported data; limited post-ACA time frame provided information on short-term changes only.
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.
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Wherry LR, Miller S. Early Coverage, Access, Utilization, and Health Effects Associated With the Affordable Care Act Medicaid Expansions: A Quasi-experimental Study. Ann Intern Med. 2016;164:795–803. doi: 10.7326/M15-2234
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Published: Ann Intern Med. 2016;164(12):795-803.
Published at www.annals.org on 19 April 2016
Cardiology, Coronary Risk Factors, Diabetes, Dyslipidemia, Endocrine and Metabolism.
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