CHICAGO (AP) _ Alarming studies suggesting that medical errors kill close to 100,000 U.S. hospital patients each year probably overestimate the problem, with the real total perhaps 5,000 to 15,000, researchers say.
In a study in Wednesday's Journal of the American Medical Association, researchers said the previous studies were flawed because there was little consensus among the doctors consulted on what constitutes a deadly error.
Also, the previous studies did not consider whether the patient would have died even if the error hadn't occurred.
Two years ago, a blistering report by the Institute of Medicine said that medical mistakes in hospitals kill up to 98,000 hospitalized Americans a year, and it demanded major changes. The mistakes included prescription drug errors and misused or malfunctioning equipment.
The numbers drew the attention of government officials _ earlier this month the Health and Human Services Department made a series of recommendations to reduce medical errors _ and hospitals nationwide have implemented new protections, such as computer programs to catch errors.
But while improvements are welcome, the number of medical errors that actually cause death is probably overblown, researchers said.
Dr. Rodney A. Hayward, who led the new study as director of the VA Center for Practice Management and Outcomes Research in Ann Arbor, Mich., estimates that between 5,000 and 15,000 deaths annually are due to errors. But he acknowledged those numbers are rough estimates.
``This is not to suggest that medical errors are unimportant,'' Hayward said. Instead, he said: ``The argument is to be careful about what you implement.''
He said he worries that reports about errors will discourage people from seeking needed treatment, and that hospitals with systems that flag every error ``might cause some to turn the system off because of all the false positive alerts that are no big deal.''
Hayward's study looked at 111 hospital deaths at seven Veterans Affairs hospitals from 1995 to 1996. Fourteen doctors were assigned to review the patients' medical records. They reported that 22.7 percent of deaths might have been prevented if the patients had received optimal care, and 6 percent of the deaths were probably or definitely preventable _ about the same as other studies.
But on closer examination, the researchers found that in almost every case in which one of the consulting doctors said error caused a death, the opinion was not that of the majority of the reviewers, and often there was no good evidence to support the finding.
Researchers also found widely varying opinions among the doctors on whether an error directly led to death, and even on what constituted an error, said Hayward, a professor of medicine and public health at the University of Michigan.
The new study estimated that only 0.5 percent of the patients would have lived at least three months in good health if the care would have been optimal.
Dr. Lucian L. Leape of the Harvard School of Public Health, co-author of the Institute of Medicine report, defended his findings and said Hayward's conclusions were based on too small of a sample and were derived by way of ``statistical torturing.''
He said that some medical professionals have argued that his study actually underestimated the number of medical errors that caused deaths.
Carmela Coyle, senior vice president for policy for the American Hospital Association, said the new study is interesting but added: ``It's not about the numbers, but focusing on improving patient safety. This does not change the immediate task at hand.''