A new study estimates medical malpractice lawsuits and defensive medicine cost about $55.6 billion a year.

That accounts for 2.4 percent of annual health-care spending, according to the study published in the September issue of Health Affairs.

It was conducted by researchers at the Harvard School of Public Health and Brigham and Women's Hospital in Boston.

The study looked at payments made to malpractice plaintiffs, defensive medicine costs, administrative costs such as lawyer fees and the costs of lost work time. Defensive medicine costs alone were estimated at $45.6 billion a year.

"Physician and insurer groups like to collapse all conversations about cost growth in health care to malpractice reform, while their opponents trivialize the role of defensive medicine," said Amitabh Chandra, a study author and professor of public policy at Harvard's Kennedy School of Government.

"Our study demonstrates that both these simplifications are wrong - the amount of defensive medicine is not trivial, but it's unlikely to be a source of significant savings," Chandra said.

Medical liability costs could be reduced by capping non-economic damages in malpractice cases, the study said.

For more information, see www.healthaffairs.org