The University of Chicago Medicine earned its 12th consecutive “A” in patient safety from The Leapfrog Group, a prominent hospital-watchdog organization.

The grade, announced Oct. 31, makes the Hyde Park-based academic health system one of only 59 hospitals in the county to earn a dozen sequential top marks since Leapfrog began producing its twice-a-year survey in June 2012. The nonprofit group’s latest survey reviewed data from more than 2,600 hospitals across the country.