The top-rated U.S. hospitals have a 27% lower death rate than other hospitals, according to a study released by HealthGrades, an independent healthcare ratings organization. Researchers analyzed the records of about 41 million Medicare patients treated at the nation's almost 5,000 non-federal hospitals. The study of data from fiscal years 2005, 2006, and 2007 focused on 26 common diagnoses and procedures. Patients treated at hospitals ranked in the top 5% nationally had a 27% lower risk of in-hospital death, the report found.