The COVID-19 pandemic led to mixed results on hospital safety, according to the latest data from the Leapfrog Group.

The Leapfrog Group assessed approximately 2,800 general acute care hospitals for the report published Tuesday. Among those, 20.3% got higher safety scores in spring 2022 than a year before and 22.4% received lower grades. The majority—57.2%—rated the same in 2021 and 2022.

North Carolina had the highest share of hospitals earning “A” grades at 59.8%. Virginia and Utah followed closely behind, with 59.2% and 55.6% of hospitals at “A” levels respectively.

Wyoming, the District of Columbia, West Virginia and North Dakota fared the worst in that regard, with no hospitals receiving “A” grades.

“We sympathize with the stress that hospitals are under,” Leapfrog Group President and CEO Leah Binder said. “At the same time, though, people are entrusting their lives in hospitals, so we hold them to a higher standard. Even under all that stress, we need them to be as safe as possible for their patients.”

Ranking hospitals based on their abilities to protect patients from preventable errors, accidents, injuries and infections enables them to identify opportunities to improve and to set goals, Binder said.

This year, 33% of hospitals received “A’s,” 24% received “B’s,” 36% received “C’s,” 7% received “D’s” and less than 1% received “F’s.” Although grades for individual hospitals have shifted, the overall picture is mostly unchanged from 2021.