Norwich — A nonprofit watchdog organization that rates hospitals on patient safety awarded Backus Hospital an “A” in its latest national rankings, Hartford HealthCare, the hospital’s corporate owner, announced.

Windham Hospital, also a Hartford HealthCare member, earned a “B” grade.

“We are extremely honored and proud to receive this prestigious distinction from The Leapfrog Group,” said Dr. Abbie Courtemanche, Hartford Healthcare’s East Region vice president of medical affairs. “Quality and safety is our top priority and these high scores for Backus and Windham hospitals are a true testament to our colleague’s hard work, skill, and dedication in delivering the best and safest care to those we serve.”

Leapfrog rates hospitals’ success in protecting patients from harm and error during hospitalizations. It assigns an “A,” “B,” “C,” “D” or “F” grade to general hospitals across the country based on more than 30 performance measures that examine errors, injuries, accidents and infections, as well as the systems hospitals have in place to prevent harm to patients.

Grades are updated twice annually, in the fall and spring.

Twenty-eight Connecticut hospitals were graded in findings published last month, with nine receiving an “A,” nine receiving a “B” and 10 receiving a “C.”

Lawrence + Memorial Hospital in New London received a “C,” as did Westerly Hospital.