A new study published in the Journal of Patient Safety suggests that there could be as many as 400,000  preventable adverse events (PAEs) that lead to death. This is more than four times the number previously estimated in 1999.  Those figures would make hospital  errors the third leading cause of death behind heart disease and cancer,  according to  Centers for Disease Control and Prevention statistics.

The latest findings are based on research conducted by John T. James, Ph.D., who oversees the  advocacy group  Patient Safety America. James analyzed four studies around PAEs and found the weighted average to be 210,000  deaths due to preventable harm in hospitals. However,  because of limitations in reporting and incomplete medical records,  he wrote that the number is likely twice that figure, more than 400,000 deaths each year.

Lucian Leape, M.D., who served on the committee that wrote the  1999 report,  told  ProPublica  that he believes James’ estimate is accurate. He said the committee knew at the time of its 1999 study that the numbers were low. The analysis at the time was based on a rather crude reporting tool, and furthermore, he said, medicine is more complex now, which leads to more mistakes.

“In a sense, it does not matter whether the deaths of 100,000, 200,000 or 400,000 Americans each year are associated with PAEs in hospitals. Any of the estimates demands assertive action on the part of providers, legislators and people who will one day become patients,” said James.