More than 238,000 deaths resulting from hospital “safety incidents” from 2004 to 2006 were potentially preventable, alleges a Web site grading service. Overall, more than 270,000 Medicare patients died during the time span, according to the HealthGrades rating service’s fifth annual “Patient Safety in American Hospitals” study.

The deaths cost the Medicare program $8.8 billion, the firm estimated. Its analysis of the records of 41 million Medicare patients found that patients at the top 5% of rated hospitals had a 43% lower chance of suffering one or more medical errors.

The 1.1 million patient safety incidents was equal to a rate of 3% of all study subjects, researchers said. The Centers for Medicare & Medicaid Services has said it will stop reimbursing hospitals for treatment of eight preventable errors starting Oct. 1, which could cut off significant payments to acute-care providers.

Of special note for long-term care providers was the rise in incidence of certain indicators over the study period: pressure ulcer incidence, post-operative respiratory failure, post-operative pulmonary embolism or deep vein thrombosis, post-operative sepsis, and post-operative abdominal wound separation/splitting.