Newswise — CHICAGO (April 24, 2020): Mammography screening is a key tenant of early breast cancer detection and has been shown to reduce breast cancer mortality.1 In states that chose to expand Medicaid under the Affordable Care Act (ACA), lower-income women now have access to mammograms at a higher rate than in states that did not expand Medicaid coverage. Under the ACA, there has been an increase in the rate of insurance coverage, generally, and in the use of preventative health services, specifically, in states that expanded their Medicaid programs, according to researchers who analyzed seven states that expanded Medicaid in 2014. Their findings are published as an “article in press” on the website of the Journal of the American College of Surgeons ahead of print in the May issue of the Journal.

“The ACA created a natural experiment in which some states expanded Medicaid and other ones did not,” according to Christine H. Rohde, MD, MPH, FACS, senior study author and associate professor of surgery at Columbia University Irving Medical Center, New York City. “This research shows that Medicaid expansion through the ACA does have a significant impact on patients, specifically in terms of insurance coverage and mammography.”

As part of the ACA, states were given the option of expanding Medicaid to cover all adults at or below 138 percent of the Federal Poverty Level. Thirty-two states, including Washington, DC, expanded Medicaid starting in 2014. [Thirty-seven states have currently expanded their Medicaid programs. Thirty-two had expanded Medicaid at the time this study was written.2]

Dr. Rohde and her team analyzed the effects of Medicaid expansion on insurance coverage from 2011-2016 and preventive breast cancer screening from 2010-2018. They looked at data from the following Medicaid expansion states: Arizona, Colorado, Iowa, Kentucky, Michigan, Minnesota, and Rhode Island. They compared data from those states with data from the following states, which did not expand Medicaid: Florida, Kansas, Nebraska, North Carolina, South Dakota, and Wisconsin.

According to their findings, 17.2 percent of the population in expansion states and 15.2 percent of the population in non-expansion states were enrolled in Medicaid in 2011. As of 2016, expansion states saw an increase to 22.1 percent enrolled in Medicaid, compared with 16.2 percent of the population in non-expansion states.

The researchers found a greater increase in mammography rates among 50- to 74-year-old women from lower income households in expansion versus non-expansion states. Specifically, among 50- to 74-year-old women who make less than $15,000 per year, the rate of mammography in expansion states was 62.6 percent in 2010, increasing to 73.8 percent in 2018. In non-expansion states, the rate of mammography for this group increased from 68.2 percent in 2010 to 69.3 percent in 2018.

According to Dr. Rohde, there are many factors that affect a patient’s treatment decisions:

  • Whether the patient has insurance
  • Whether the patient is getting mammograms
  • If cancer shows up on the mammogram, whether the patient sees a breast surgeon for a mastectomy, if needed
  • If the patient has a mastectomy, whether she sees a plastic surgeon for reconstruction

“There are distinct steps in navigating through the health care system where having insurance or not can play a role in whether you progress through that track,” Dr. Rohde said.

“These results demonstrate that when given the opportunity, people take advantage and enroll in available insurance and that this expanded eligibility may more preferentially benefit historically underprivileged groups such as those of lower socioeconomic status,” the researchers concluded.

The current study is part of a multi-stage analysis. Dr. Rohde and her fellow researchers also plan to study the effect of Medicaid expansion on mastectomy and reconstruction rates in the future.

Dr. Rohde’s coauthors are Yoshiko Toyoda, MD, and Ishani D Premaratne, BA, of Columbia University Irving Medical Center/NewYork-Presbyterian Hospital, division of plastic and reconstructive surgery, department of surgery; and Eun Jeong Oh, MA, and Codruta Chiuzan, PhD, of Columbia University Mailman School of Public Health, department of biostatistics.

“FACS” designates that a surgeon is a Fellow of the American College of Surgeons.

This research was supported in part by the Weill Cornell Medicine Dean’s Diversity and Healthcare Disparity Research Award. 

Citation: Toyoda Y, Oh EJ, Premaratne ID, et al. Affordable Care Act State-Specific Medicaid Expansion: Impact on Health Insurance Coverage and Breast Cancer Screening Rates. J Am Coll Surg. 2020; 230(5): 775 83. DOI:


1 Nelson HD, Tyne K, Naik A, et al. Screening for breast cancer: an update for the U.S. Preventive Services Task Force. Ann Intern Med. 2009;151(10):727-737, W237-242.

2 Status of State Medicaid Expansion Decisions: Interactive Map. Kaiser Family Foundation. Available at: Accessed: April 23, 2020.

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About the American College of SurgeonsThe American College of Surgeons is a scientific and educational organization of surgeons that was founded in 1913 to raise the standards of surgical practice and improve the quality of care for surgical patients. The College is dedicated to the ethical and competent practice of surgery. Its achievements have significantly influenced the course of scientific surgery in America and have established it as an important advocate for all surgical patients. The College has more than 82,000 members and is the largest organization of surgeons in the world. For more information, visit

Journal Link: Journal of the American College of Surgeons