Physicians and insurers are taking exception to a medical malpractice study published Jan. 28 in the New England Journal of Medicine.

“Once again a study of medical liability claims has based unreliable conclusions on information obtained from the inherently flawed National Practitioner Data Bank,” Dr. Steven J. Stack , president of the American Medical Association, said in an interview.

David M. Studdert, Sc.D., of Stanford (Calif.) University, lead author of the study, said that he stands behind the findings, saying that the methodology used was strong and any significant limitations were noted.

“The data bank is the most authoritative repository of information that we have on medical malpractice claims nationwide,” Dr. Studdert said in an interview. “We don’t have an ability to look across the country at what’s happening with medical malpractice claims in any more comprehensive way than the [data bank]. Is it a perfect source of data? No. It has some limitations.”

The National Practitioner Data Bank (NPDB) is a congressionally mandated repository of medical malpractice payments and certain adverse actions related to health care providers, entities, and suppliers. Dr. Studdert and his colleagues calculated the cumulative distribution of paid claims in two physician populations: U.S. doctors with one or more paid claims and all active U.S. physicians, finding, on summation, that if physicians had one claim paid against them, they were more likely to have a subsequent claim paid against them as well (N Engl J Med. 2016; 374:354-62).

The credibility of the data bank has long been in question. An investigation published by the Government Accountability Office (GAO) in 2000 found that reports collected by the data bank were often untimely, inaccurate, or duplicated, which made it appear that “twice the number of disciplinary actions against a practitioner had been taken.”

In addition, most reports in the NPDB are based on legal settlements that were never adjudicated by a court, proven to involve negligence, or settled with a physician’s consent, according to Dr. Stack of the AMA. “Settlement information offers an incomplete and often misleading indicator of physician quality and competence. The nation’s best physicians who practice cutting-edge medicine and take on the riskiest cases are involved in settlements, yet the [NPDB] information does not acknowledge their high-level of competence.”

The study acknowledged that only 3% of the lawsuits studied were paid through trial verdicts, and that the remaining claims were paid by out-of-court settlements. Dr. Studdert and his colleagues also pointed out that payments do not necessarily indicate that a claim has merit, but that paid claims are “much more likely than unpaid claims to involve substandard care.”

Another study limitation was the unknown extent of underreporting to the NPDB, Dr. Studdert said.

As for the GAO report, the findings analyzed disciplinary actions, while the current study evaluated medical malpractice claims, Dr. Studdert said. Investigators tested for duplicate records during the course of their study and did not find repeated cases.

“That wasn’t an issue with the data we examined,” he said. “The information was very complete. I don’t doubt that the GAO report was correct, but it looks like over the last 15 years there must have been some improvements to the quality of the data bank.”

PIAA , a national trade association that represents medical liability insurers, expressed concern over findings that certain specialists face more claims than others.

“We know that certain specialties, such a neurosurgery, obstetrics and gynecology, and others, have been linked with a higher frequency of claims,” PIAA President and CEO Brian K. Atchinson said in a statement. “These doctors experience more claims because of the risk associated with their particular specialty, and not because they are inherently prone to making mistakes more often than their colleagues.”

“Studies have shown that all physicians are likely to be named in at least one medical liability claim during the course of their career with some subject to more based on their specialty,” P. Divya Parikh, PIAA vice president of research, said in a statement. “Thus, this study hasn’t really revealed anything we didn’t already know.”

Dr. Studdert said that he disagrees. “That’s really not an accurate analysis of what our analysis does. Our analysis controls for specialty and then looks at other risk factors for recurrent claims. It’s a regression model.”

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