When patients visit a doctor with their first complaint of low back pain, researchers say the evidence usually doesn't justify an imaging exam to see what might be wrong.

Yet in 2014, doctors in Minnesota ordered more than 10,000 imaging exams for these patients at a cost of $3.7 million, according to a new state report.

Imaging for patients when they first report low back pain is one of 18 examples of "low-value" care where researchers say medical procedures for most don't provide much benefit and have the potential to cause harm.

A Minnesota Department of Health report released last week found that Minnesota in 2014 spent $54.9 million on such medical services, including $9.3 million in out-of-pocket costs for patients.

"This is really the tip of the iceberg," said Dr. Rozalina McCoy, an endocrinologist, primary care physician and health services researcher at the Mayo Clinic in Rochester who worked on the health department report. "We used to think that more is better — more health care equals more health. … That's not actually true."

Researchers, physicians and employers have been paying more attention to low-value health care, particularly as health care costs continue their inexorable rise.

In 2012, the American Board of Internal Medicine Foundation launched a campaign called Choosing Wisely to educate physicians about how they could improve care and reduce unnecessary spending by avoiding overused or misused tests and procedures that provide little benefit. Over time, a number of physician groups and Consumer Reports magazine joined the effort.

Last year, researchers looked at claims data for 1.46 million patients collected by Optum, the Eden Prairie-based data division at UnitedHealth Group, and found that nearly 115,000 patients used one of 28 low-value services during 2013. The study tallied $32.8 million in spending on the services and accounted for about 0.5 percent of total spending for patients that year.

In May, speakers highlighted the issue during a conference in Edina sponsored by the Minnesota Health Action Group, a Bloomington-based coalition of large employers.

"The use of low-value care is more than just a small problem in the United States," said Paulette Daniel, an employee benefits manager at Emerson, while addressing more than 100 people gathered for the event. Daniel works for a local division of the St. Louis-based manufacturer that is educating workers about the Choosing Wisely campaign.

"Now more than ever, the relationship between out-of-pocket cost and choice of treatment options makes it incumbent on us to provide our employees with more and different information — information that will help them get the care they need," she said. "And in helping employees better understand how to select the care they need, we also need to help them understand what kind of care they don't need."

Some are skeptical, fearing that health plans and the government will use the "low value" label to lower costs at the expense of decisionmaking between doctors and patients. And while momentum might be building in some circles to reduce low-value care, at least one study suggests the impact has been limited thus far.

"Our analysis suggests that Choosing Wisely recommendations combined with patient-level consumer incentives might be insufficient to reduce low-value medical care," researchers wrote earlier this year in a Health Affairs study on the use of low back imaging.

Researchers hope the new report will bring fresh attention to the issue, since it draws on a unique database covering almost all Minnesotans.

While medical societies and consumer groups argue there are hundreds of medical services that should be considered low-value, the health department study focused on 18 diagnostic imaging tests and disease screenings where there is particularly wide agreement about their limited worth, said Stefan Gildemeister, the state's health economist. All the services have value for some patients depending on their age or health history, Gildemeister said, but the report zeros in on the patients for whom the benefits are marginal at best.

The report found that doctors in 2014 provided more than 47,000 head imaging tests for patients with uncomplicated headaches, making it the most common low-value service documented. The imaging tests generated more than $22 million in costs, the largest single chunk of spending.

Researchers believe the estimates are low, if anything, because they applied very tight definitions for patients included in their tallies for low-value care. Headache patients, for example, who received an imaging exam were included in the count only if they didn't have any of 10 or more diagnoses that might justify the procedure.

"There is really broad clinical agreement that these services only rarely should be delivered for the patients and clinical circumstances described," Gildemeister said. "The chance that in certain circumstances the service would have been high-value is low ­— super low."

For years, health systems have been trying to reduce low-value services, but the report provides new insights nonetheless, said Dr. Rod Christensen, vice president of medical operations at Minneapolis-based Allina Health System. The concern over imaging for patients with simple headaches "wasn't on my radar," Christensen said, adding: "That will be on my list now."

Low-value services will never be completely eliminated because there are always special circumstances that might not be apparent to outside reviewers, said Dr. Charlie Fazio, medical director at HealthPartners, a Bloomington-based health insurer. Clinicians always need the freedom, he said, to make exceptions for patients.

"But I think you can see based on the numbers and the percentages the way they are, that we've got some room to go before we conclude that everybody who is getting low-value care is somehow in that exception group," Fazio said.

Sometimes doctors resort to providing low-value services because they don't have time to patiently review the pros and cons with patients who are understandably concerned, said McCoy of the Mayo Clinic. What's needed is a culture change for doctors and patients, she said, since unnecessary care creates a potential for harm.

"It's not just about reducing cost," McCoy said. "It's about improving the quality and quantity of life for my patients."