A new study has thrown light on the medical malpractice going on in the US and has estimated its cost at $55.6 billion a year, which is 2.4 per cent of annual health-care spending.

Defensive medicine costs are included in the estimate and totals to $45.6 billion. Defensive medicine costs are when doctors avoid lawsuits and prescribe unnecessary tests or treatments.

Researchers at Harvard University and Brigham and Women's Hospital in Boston said that health-care inefficiencies happen due to defensive medicine and apart from this medical errors and avoidable patient injuries also take place.

It has not been figured out that what is the actual cost of medical liability in the United States. But authors of this study claim their analysis to be reliable and comprehensive.

Study author Michelle Mello, a professor of law and public health at the Harvard School of Public Health, said, "We cannot debate the potential for medical liability reform to bring down health-care costs in any meaningful way without realistic cost estimates. Some of the numbers bandied about in policy discussion were quite imaginative and we wanted a more defensible estimate."