Five New Hampshire hospitals received an A in hospital safety, according to new grades released by The Leapfrog Group on Tuesday. The hospital safety grades are released by the nonprofit group twice a year, in the spring and in the fall. The grades released on Tuesday showed that five states — Oregon, Rhode Island, Hawaii, Wisconsin and Idaho — showed significant improvement since the safety grades were first implemented in 2012.

"Errors and infections in hospitals are the third leading cause of death in America, and people deserve to know which of their hospitals are best at preventing them," Leah Binder, president and CEO of Leapfrog, said in a press release. Medical errors, accidents, injuries and infections are taken into account by Leapfrog when calculating the grades. The goal of the rankings is to determine a patient's risk of further injury or infection if they visit a certain hospital.

Leapfrog assigns A,B,C,D and F letter grades to general acute-care hospitals in the United States. Leapfrog explains that the safety grade includes 27 measures that are taken together to produce a single letter grade representing a hospital's overall performance in keeping patients safe from preventable harm and medical errors. The group uses performance measures from a variety of sources, including the Centers for Medicare & Medicaid Services, the Leapfrog Hospital Survey and the Centers for Disease Control and Prevention. (You can read more about the letter grades here.) Here's the grades New Hampshire hospitals received, according to Leapfrog:

Frisbie Memorial Hospital, Rochester - A Parkland Medical Center, Derry - A Elliot Hospital, Manchester - A Concord Hospital - A Cheshire Medical Center, Keene - A Portsmouth Regional Hospital - B Wentworth-Douglass Hospital, Dover - B Southern New Hampshire Medical Center, Nashua - B Lakes Region General Hospital, Laconia - B Catholic Medical Center, Manchester - C Dartmouth-Hitchcock Medical Center, Lebanon - C St. Joseph Hospital of Nashua - D Leapfrog notes that of the 2,632 hospitals graded in Tuesday's update, 832 earned an "A," 662 a "B," 964 a "C," 159 a "D" and 15 an "F."

Story by Feroze Dhanoa, Patch National Staff