High-profile medical errors such as operating on the wrong body part or receiving a mistaken dose of drugs should take a back seat to a far more common and insidious mistake, a new report reveals.For the fifth straight year, an analysis of errors in the nation’s hospitals found that the most reported patient safety risk is a little-known but always-fatal problem called failure to rescue.

From 2004 through 2006, patient safety errors resulted in 238,337 potentially preventable deaths of U.S. Medicare patients and cost the Medicare program $8.8 billion, according to the fifth annual Patient Safety in American Hospitals Study.This analysis of 41 million Medicare patient records, released April 8 by HealthGrades, a health care ratings organization, found that patients treated at top-performing hospitals were, on average, 43 percent less likely to experience one or more medical errors than patients at the poorest-performing hospitals.