As high-deductible health insurance becomes more common in the United States, and especially in Minnesota, it may be causing men to make fewer trips to the emergency room — even when they have dangerous conditions such as kidney stones or heart trouble.

Men whose employers switched to such policies cut their ER use by nearly 20 percent the first year they were covered, according to a new study by researchers at the University of Minnesota and at Harvard Medical School.

They said it was "concerning" that ER use dropped just as sharply for severe conditions — such as an irregular heartbeat — as for minor conditions, such as a sore throat.

"Men who transition to [high-deductible plans] may forego needed care in the immediate term, resulting in delays or increased severity of illness when care is later sought," they wrote. The study was published Tuesday in the online journal Medical Care.

Women scaled back ER visits for minor complaints but not for severe conditions, according to the study, the first to break out gender patterns as they relate to high-deductible insurance.

The study adds to a growing debate over whether raising consumers' out-of-pocket health care costs leads people to scale back unnecessary doctor visits, as intended, or to skip needed medical care.

"This research should give policymakers reason to pause and ensure that changes associated with the Affordable Care Act, including the potential for further increases in the percentage of Americans with high-deductible plans, are carefully and systematically evaluated," said Katy Kozhimannil, the lead author and a professor in the U's School of Public Health. "We need to monitor impacts of changes in health insurance coverage on the quality of care."

Insurance policies that require consumers to pay more out of pocket have spread rapidly in the last decade, buoyed by the theory that they will reduce overall health spending and keep premiums affordable. The number of people covered by such plans has tripled since 2006, affecting 13.5 million Americans.

Minnesota ranks No. 2 nationally, with more than 14 percent of insured people using high-deductible coverage, according to America's Health Insurance Plans, a trade group.

A 2011 Mayo Clinic study found that employees who faced higher co-pays for care cut their use of discretionary services, such as certain scans, but not essential preventive care.

Vulnerable?

The study used health insurance billing data for more than 12,000 members of Harvard Pilgrim Health Care, whose employers switched from prepaid HMO coverage to high-deductible plans between 2001 and 2008.

Overall, low-severity visits such as for a headache or a sore throat decreased by 21 percent in men, while high-severity visits such as for kidney stones and irregular heartbeats decreased by 34 percent.

In women, the study found fewer ER trips overall, but no decrease in visits for severe problems.

Although other research has found that men are less likely to seek and receive needed care, the researchers said, the study still contradicted many stereotypes.

"We usually don't think about men being vulnerable, we don't think about men being at risk," Kozhimannil said.

Ashley Griffin • 612-673-4652