Physicians in states that limit the amount juries can award for noneconomic damage in medical malpractice suits conduct fewer invasive tests for suspected coronary artery disease (CAD) and referred fewer patients for revascularization than their counterparts in states with no caps on medical liability.

Results of a study led by Steven A. Farmer, MD, from the Center for Healthcare Innovation and Policy Research at George Washington University, Washington, DC, show that physicians in nine “new-cap” states substantially changed their approach to CAD testing and management compared with physicians in 20 states with no caps.

“To our knowledge, ours is the first paper to show changes in clinical behavior following up cap adoption in the particular setting of CAD testing and treatment,” the authors write.

“Our study suggests that physicians who face lower malpractice risk may be less concerned with that risk, and thus more receptive to new care delivery strategies associated with alternate payment models,” they conclude.

The difference-in-differences study, conducted jointly by researchers at George Washington and Northwestern universities, was published online June 6 in JAMA Cardiology.

Defensive Medicine

Physicians often report practicing “defensive” medicine to reduce malpractice risk, including performing expensive but marginally beneficial tests and procedures, the researchers write.

Many states have adopted noneconomic damage caps that compensate plaintiffs for “pain and suffering,” they note. Previous studies of malpractice reforms, including damage caps, have shown little evidence that such changes affect overall healthcare spending, and none of these studies has evaluated whether or how changes in malpractice risk affect clinical decision making, especially in the face of an uncertain diagnosis, the researchers write.

Clinicians in new-cap states ordered the same overall number of tests for ischemia, but they were less prone to rely on angiography as a first diagnostic test and more likely to order less definitive, noninvasive stress testing, they report.

In addition, fewer patients were referred for angiography following initial stress testing. Physicians in new-cap states also performed fewer percutaneous coronary intervention (PCI) procedures after ischemic evaluation, suggesting that they were more likely to rely on medical therapy, study authors note.

Table. Change in Practice in States With vs Without Caps on Medical Liability

Endpoint Relative Change (95% Confidence Interval) (%) PValue
Angiography as first diagnostic test –24 (–40 to –7) .005
Noninvasive stress testing 7.8 (–3.6 to 19.3) .17
Referral for angiography after initial stress testing –21 (–40 to –2) .03
PCI after ischemic evaluation –23 (–40 to –4) .02