Out-of-hospital cardiac arrest incidence among middle-aged adults declined significantly in an urban county in Oregon during the period of Medicaid expansion under Obamacare, researchers report.
The timely findings from a pilot study add to the evidence linking community-wide health insurance expansion to improved cardiovascular preventive care and outcomes, wrote Eric Stecker, MD, of Oregon Health & Science University, Portland, and colleagues.
The study was published online Wednesday in the Journal of the American Heart Association; it’s the third in as many days in a major journal to link insurance status to specific health outcomes, including overall mortality and timely breast cancer diagnosis.
In an interview with MedPage Today, Stecker said cardiac arrest may represent a uniquely sensitive indicator of the impact of insurance status on mortality for several reasons.
“There are very few warning signs for cardiac arrest, and the mortality rate is very high — between 90% and 95%,” he said. “Also, cardiac arrest is very sensitive to preventive care over a relatively short period of time.”
He noted that among middle-aged and older-adults, unrecognized and recognized coronary artery disease is a major cause of cardiac arrest.
“There are about 350,000 cardiac arrest deaths in the U.S. every year, and these deaths are sudden and largely unheralded,” Stecker said. “Treatment of unrecognized cardiovascular disease or risk factors can result in a lower risk for cardiac arrest within a 12- to 24-month time frame.”
Using U.S. Census and emergency medical service dispatch data from Multnomah County, Ore. (2015 adult population, 636,000), the researchers compared out-of-hospital cardiac arrest (OHCA) incidence among middle-aged (45 to 64 years old) and Medicare eligible (age 65 and older) residents at two time points — 2011-2012 and 2014-2015 — before and after Medicaid expansion under the Affordable Care Act.
“The change in OHCA incidence for the middle-aged population exposed to insurance expansion was compared with the elderly population with constant near-universal coverage,” the researchers wrote.
The number of adult OHCA cases of presumed cardiac etiology was 844 in the pre-expansion time point and 834 in the post-expansion time point.
The middle-aged, pre-Medicare eligible population experienced a 17% reduction in OHCA incidence (95% CI 4%-31%) following Medicaid expansion, while no significant change in OHCA incidence was seen in the older population.
The number of uninsured middle-aged residents of Multnomah County declined abruptly following expansion, while it remained stable among the Medicare eligible participants.
“Among middle-aged adults, Medicaid expansion was responsible for the greatest reduction in uninsurance, while coverage from employer-based insurance did not change,” the researchers wrote.
Stecker noted that the study was not large enough, and the population not diverse enough, to control for all confounding variables, such as increases in smoking cessation and changes in the delivery of medical care in Oregon following Medicaid expansion.
“That is why we consider this a pilot study,” he said. “This study alone is not definitive, but the findings support those of prior studies showing that improving access to insurance also improves engagement in preventive care and outcomes.”
In Massachusetts, which expanded Medicaid years before Obamacare became law, a 2014 analysis showed that deaths from all causes and from causes amenable to healthcare declined in the post-expansion period.
Stecker and colleagues concluded that based on the Massachusetts experience, and findings from their pilot study, “further investigation in larger populations using quasi-experimental analytic techniques is warranted and feasible.”
In an editorial published with the study, Mary Fran Hazinski, RN, of Vanderbilt University in Nashville, and Carole Myers, PhD, RN, of the University of Tennessee in Knoxville, also called for larger studies examining the impact of healthcare access on cardiac arrest mortality.
“The hypothesized relationship between healthcare expansion and decline in [out of hospital cardiac arrest] incidence is certainly a timely question that requires further study,” they wrote. “A follow-up study should be based on a framework that looks more broadly at a complement of social and other determinants of health, and accounts for the various dimensions of access, and evaluates access by looking at utilization.”
Funding for this research was provided by the National Heart, Lung and Blood Institute.
The researchers declared no relevant relationships with industry related to this study.
F. Perry Wilson, MD, MSCE Assistant Professor, Section of Nephrology, Yale School of Medicine and Dorothy Caputo, MA, BSN, RN, Nurse Planner