High-deductible health plans and major cardiovascular outcomes

Cardiovascular disease kills more people in the U.S. than any other condition, accounting for 30% of deaths in 2017. Improvements in cardiovascular mortality began slowing a decade ago and major adverse cardiovascular events such as stroke and myocardial infarction began increasing among adults under age 65. Reasons for these trends are unclear, but experts have proposed causes such as the earlier onset of cardiovascular risk factors, stagnation of preventive care, and a change in health insurance coverage in the U.S. Concerns about the contribution of health insurance to these trends are based on the rapid expansion of HDHPs and previous research about health effects of high out-of-pocket costs.

The study team examined the effects of a transition to a HDHP on the risk of major adverse cardiovascular outcomes such as myocardial infarction and stroke. The study population, drawn from a large national health insurance plan, included individuals with risk factors for cardiovascular disease who were continuously enrolled in low-deductible (<$500) health plans during a baseline year followed by up to 4 years in high-deductible (≥$1000) plans after an employer-mandated switch. The matched control group included individuals with the same risk factors who were contemporaneously enrolled in low-deductible plans. The researchers studied time to first major adverse cardiovascular event, defined as stroke or myocardial infarction.

Study findings show that HDHP members did not experience an increase in major adverse cardiovascular events compared with individuals in low-deductible plans. "Based on previous high-deductible health plan research, we had hypothesized that those with risk factors for cardiovascular disease would experience increases in major adverse cardiovascular events after a switch to high-deductible health plans, but this did not turn out to be the case," said Frank Wharam, lead author and Associate Professor of Population Medicine at the Harvard Pilgrim Health Care Institute and Harvard Medical School. Dr. Wharam adds, "HDHPs typically include features such as low or no out-of-pocket costs for medications and preventive services. Our study detected small changes in cardiovascular medication use and preventive services which may have protected HDHP members from increased adverse cardiovascular events.

These findings provide a measure of reassurance that HDHP enrollment was not associated with an appreciable increased risk of major adverse cardiovascular outcomes. But researchers caution that policymakers and employers should remain careful in promoting HDHPs among low-income and other vulnerable patients given the potential for adverse financial and health outcomes that this study did not address. Research should also extend follow up time to better assess long-term outcomes and should examine whether people with HDHPs ultimately require more intensive workups and more advanced treatments for cardiovascular events.