This analysis of patient safety in Medicare patients from 2005–2007 concludes that while modest improvements have been made, patient safety incidents still account for nearly 100,000 preventable deaths and nearly $7 billion in excess costs yearly. The report also recognizes the best performing hospitals with a "Patient Safety Excellence Award"—hospitals scoring in the top 15% according to a ranking methodology developed by the authors. As with prior HealthGrades reports, the study uses the Agency for Healthcare Research and Quality (AHRQ) Patient Safety Indicators (PSIs) to measure the incidence of patient safety problems and compare hospitals. The limitations of using PSIs as a performance measure have been discussed in a prior study and AHRQ WebM&M commentary, and it is important to note that this report did not undergo external peer review.