More than 200,000 people die every year from medical negligence in hospitals in the United States, according to a study in the Journal of Patient Safety. The study estimates that "between 210,000 and 440,000 patients each year who go to the hospital for care suffer some type of preventable harm that contributes to their death." This number is significantly larger than a widely cited estimate of 98,000, which was established in the Institute of Medicine’s 1999 "To Err Is Human" report. It is also larger than the Office of Inspector General for Health and Human Services’ estimate in 2010 than 180,000 Medicare patients die annually as a result of poor hospital care.
The estimate of 210,000 - 440,000 was released last year in a study by John T. James. James was a toxicologist for NASA until retiring earlier this year. He continues to run the advocacy organization Patient Safety America, which he founded after his 19-year-old son died as a result of "uninformed, careless, and unethical care," at a hospital in Texas in 2002.
James used a screening method known as the Global Trigger Tool to gather data for the study. The tool "guides reviewers through medical records, searching for signs of infection, injury or error. Medical records flagged during the initial screening are reviewed by a doctor, who determines the extent of the harm." ProPublica continues:
In the four studies, which examined records of more than 4,200 patients hospitalized between 2002 and 2008, researchers found serious adverse events in as many as 21 percent of cases reviewed and rates of lethal adverse events as high as 1.4 percent of cases.
By combining the findings and extrapolating across 34 million hospitalizations in 2007, James concluded that preventable errors contribute to the deaths of 210,000 hospital patients annually.
That is the baseline. The actual number more than doubles, James reasoned, because the trigger tool doesn't catch errors in which treatment should have been provided but wasn't, because it's known that medical records are missing some evidence of harm, and because diagnostic errors aren't captured.
This estimate would make medical negligence in hospitals the third-leading cause of death in the country behind heart disease and cancer.