JAMA Network Open Study: HDHPs Not Associated With Major Adverse Cardiovascular Events

July 26, 2020

Study allays some concern that high-deductible health plans cause people to put off care, although authors urge caution in interpreting the results.

Most Americans with commercial health insurance are now in high-deductible health plans (HDHPs). The coverage is a trade-off: lower premiums (employers like that) but with that comes exposure to higher out-of-costs. Some healthcare policy experts have been wary of HDHPs. Results from the famous RAND Health Insurance Experiment in the ’70s and ’80s found that high-cost sharing could lead to poorer health outcomes among the poorest and sickest in a population of covered lives, although the overall conclusion of the study was that modest cost sharing was not associated with negative cost sharing. Studies since have found that high deductibles are associated with poor outcomes for low-income people.

Underlying the skepticism HDHPs is that cost sharing causes people to put off healthcare — going to the doctor, getting a prescription — and that the delay results in people missing out on preventive steps and early interventions that, on average, keep people healthier.

But results of a study published last week in JAMA Network Open suggests that some of the worry HDHPs is misplaced. J. Frank Wharam, M.D., M.P.H., and his colleagues reported results showing that enrollment in n HDHP plan was not associated with an increased risk of a major cardiovascular event, such as a heart attack or stroke, among people who are more likely to experience one. What’s more, HDHPs didn’t increase the risk among some important subgroups — people with diabetes, for example.

The thought bubble: So maybe HDHPs aren’t so bad after all.

But Wharam, who is director of the Division of Health Policy and Insurance Research in the Harvard Medical School Department of Population Medicine, and his colleagues suggest caution in interpreting their results and offered several explanations. Recent versions of HDHPs have low or zero out-of-pocket costs for medications and preventive services. An HDHP that removes those costs may remove an impediment to getting the kind of services that stave off a heart attack, stroke or some other cardiovascular event. Of course, this caveat argues in favor of the current version of HDHP.

Another reason for their findings, say Wharam and his co-authors, may be that the deductibility threshold of $1,000 that they used to define an HDHP is quite low. They ask whether the HDHPs would be so benign with respect to cardiovascular events were the threshold (and more in keeping with current deductibles used In HDHPs) Finally, they said the results may change with a longer follow-up period. And, as with any observational studies, there’s a question about whether confounding factors might have explainedthe outcome.

Still, these finding definitely adds a twist to the HDHP plot. It isn’t a study that can be dismissed because it was small. Wharam et al. used data from a large national commercial insurer and Medicare Advantage. The high-deductible “intervention” group included about 160,000 people who were switched into to high-deductible ones by their employers. The control group included almost 1.5 million people who stayed low deductible plans. People in both groups were at heightened risk for a “major adverse cardiovascular event” by virtue of having diabetes, high blood pressure, high cholesterol, or cardiovascular disease.

“Our findings provide a measure of reassurance that HDHP enrollment was not associated with an appreciable increased risk of major adverse cardiovascular outcomes during four follow-up years,” wrote the researchers, a team that included Joseph P. Newhouse, Ph.D., who was project leader of the RAND Health Insurance Experiment. But they also cautioned against promoting HDHPs among low-income people (they said that their study was not powered to look at vulnerable subgroup) and recommended that researchers look into HDHPs with and without features such as exempting medication from the deductible. They noted a rule change they pointed to a federal government decision last year that allows HDHPs with health savings accounts to exempt “secondary preventive medications” — such as those for controlling diabetes — from the annual deductible.