What If We Couldn't Sue Our Doctors for Malpractice?

During childbirth, are doctors more likely or less likely to intervene surgically if liability is a concern? A study co-authored by an economist at Massachusetts of Technology (MIT) and a professor of law and economics at the Duke University, offers insight on this interesting question about "defensive medicine."

The research, based on evidence from the U.S. Military Health System, finds that when doctors have immunity from liability lawsuits, they actually perform slightly more C-section operations, compared to when they are legally liable for those operations — about 4% more, over a 10-year period.

“When you’re worried about errors of commission, defensive medicine can lead to [less] treatment of patients,” said Jonathan Gruber, an MIT economist and co-author of a new paper detailing the study’s findings.

The paper, “Defensive Medicine and Obstetric Practices: Evidence from the Military Health System,” is published this month in the Journal of Empirical Legal Studies. Gruber's co-author is Michael Frakes, a professor of law and economics at the Duke University School of Law.

According to the paper, 74% of obstetricians and gynecologists face malpractice claims by age 45, compared to 55% of physicians in the area of internal medicine.

To conduct the study, Gruber and Frakes used Military Health System data to conduct what economists call a “natural experiment,” in which two otherwise similar groups of people are divided by one circumstance — often a policy change or social program. U.S. military members receiving treatment from military facilities can't sue their military physicians or facilities for medical malpractice. However, the authors claim that military personnel can also opt to receive private care outside of a military base. This, they say, generates two pools of otherwise similar people, divided by their two care options — one with no liability for doctors, and one with liability. The idea for doing a study based on this comparison occurred to Gruber while he was working with the Military Health Service on other healthcare delivery issues.

“For decades, health economists have been searching to find the holy grail of a natural experiment to tell us what would happen if people couldn’t sue for malpractice,” Gruber said.

The study examines Military Health System data on 1,016,606 births in military families, from 2003 to 2013. About 44% of the deliveries occurred at military health facilities and 56% at civilian hospitals. Ultimately, as the study shows, C-sections are about 4% more common during the deliveries at military hospitals, compared to the times when mothers in the Military Health System deliver at civilian hospitals.

Gruber says that finding will seem unexpected to those who associate defensive medicine with an increase in operations, treatment, and interventions.

“We tend to think of defensive medicine as … doctors doing extra testing because they’re afraid of getting sued,” he says. But this finding indicates that, in childbirth settings, doctors practice defensive medicine by intervening slightly less.

For more on this study and an earlier paper by Gruber and  Frakes, check out the full MIT News story.