(Jeff Roberson/AP)

A possible unintended consequence of one of health reform's biggest goals — curbing excess health care spending — could be a surge in malpractice lawsuits, a provocative study published in the British Medical Journal Wednesday suggests.

Researchers tracked more than 24,000 Florida physicians over a nine-year period and found that in six specialties, doctors who spent the most health-care resources on hospitalized patients had the lowest likelihood of being sued. It's the kind of pattern that raises more questions than it answers: The data does not demonstrate that higher spending caused lawsuits to decrease or reveal whether higher spending resulted in fewer medical errors.

"We need to figure out whether it’s the case that spending more by physicians reduces liability," said Anupam Jena, associate professor of health-care policy at Harvard Medical School, who led the study. "The overall goals in health-care reform are to reduce spending. So that strategy has relied on physicians to reduce spending and overutilization, but by doing so you could imagine their liability risk goes up, and that could be a potential obstacle to getting physicians to buy in to what we’re trying to do as a society with health care."

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For years, doctors have reported taking measures to avoid possible liability — preventing lawsuits, not disease. That can include unnecessary imaging scans, blood work, or even a hospital admission. In the United States, defensive medicine has been estimated to cost $60 billion per year. What no one has really understood is whether defensive medicine works — does it reduce the likelihood of being sued?

The study suggests the answer is yes. A clear pattern emerged in which doctors that used the most medical resources per patient had the lowest risk of being sued that year. For example, internal medicine doctors whose patients on average racked up the highest hospital charges — nearly $40,000 per hospital admission — had a 0.3 percent likelihood of getting hit with an allegation of malpractice. Those who had patients with the lowest hospital charges, about half the amount, were five times as likely to be sued. Obstetricians with the highest rate of Caesarean sections, often pointed to as a form of defensive medicine, were about half as likely to be slapped that year with malpractice suits than those who did the fewest C-sections.

There are a slew of limitations to the study: It was limited to a single state, it couldn't account for differences in the severity of illness between patients, and it could merely note correlations between the level of spending and the likelihood of lawsuits.

If the pattern is borne out in other studies and it turns out greater spending does, indeed, protect doctors against lawsuits, it is also unclear why. If the greater spending means fewer errors are made, it would be beneficial to patients and doctors. But it might be that deploying more medical resources made patients hesitant to sue — an outcome that may protect the doctor, but isn't really in anyone's best interests.

An accompanying editorial called the results "noteworthy." The study is "the first to substantiate a common assumption that if doctors spend more and use more resources, they are less likely to be sued," wrote Tara Bishop and Michael Pesko of Weill Cornell Medical College.

But Bishop and Pesko also noted the many limitations. One possibility, for example, is that the highest-spending doctors had already been sued previously, and were spending more or taking other precautions to improve communication with patients to avoid it happening again.

Inconclusive though it is, the study comes at a timely moment. New payment systems value quality over quantity, a correction to the current system that can incentivize over-treatment, since doctors are paid for each test and procedure.

But there's a central tension. The interests of individual patients and doctors won't always be aligned with what's best for the health-care system. Cutting back on truly excessive testing and procedures will benefit everyone, but any individual person might feel uncomfortable with the idea the doctor might be holding back on care for any reason. Doctors, on the other hand, may be reluctant to curb spending since it may protect themselves against accusations of malpractice.