Seventeen of 46 Minnesota hospitals that were included in a recent national study received an “A” rating for safety, ranking Minnesota ninth among states based on its percentage of top-rated hospitals.

That’s according to a recent report by The Leapfrog Group, a Washington, D.C.-based nonprofit comprising health-care purchaser members.

To award hospitals an A through F letter grade, The Leapfrog Group examined publicly available data on patient injuries, medical and medication errors, and infections. The Leapfrog Group rated 2,652 U.S. hospitals for which there was sufficient public data; not all U.S. hospitals were scored.

The 10 states with the highest percentage of A-rated hospitals are Massachusetts (74 percent), Maine (70 percent), Vermont (50 percent), Illinois (44 percent), Michigan (44 percent), Tennessee (43 percent), Virginia (41 percent), Delaware (40 percent), Minnesota (37 percent), and California (36 percent).

Rhode Island ranked lowest, with none of its hospitals receiving an A grade. Only six percent of hospitals in Missouri, Oregon, and Arkansas received an A grade; Oklahoma rounded out the bottom five states for safety, with 12 percent of its hospitals getting an A grade.

“More than 400 people die every day from hospital errors such as medication mix-ups, accidents, and infections,” Leapfrog Group president and CEO Leah Binder said in a press release. “Ultimately, we want all hospitals to get ‘A’s. But it is interesting to see that hospitals in some parts of the country seem to be particularly focused on safety.”

Access the full state-by-state ranking here.

The Leapfrog Group has not released individual hospital grades for 2012. Scores awarded to hospitals in 2011 can be searched here.