The Leapfrog Group has released its most recent patient safety grades. The Washington D.C.-based non-profit national patient safety organization gave a "D" grade to 6 of 13 hospitals in the Western New York area.

The group graded 2,500 hospitals nationwide based on adherence to hand hygiene, rate of bedsores, ICU staffing, hospital-acquired illnesses and about 22 other measures.

The best in the area? Kenmore Mercy, which earned a "B."

Hospitals in WNY that earned a "C" -- Mt. Saint Mary's (Lewiston), ECMC, Olean General, Brooks Memorial (Dunkirk), Sisters and Mercy.

Hospitals in WNY that earned a "D" -- DeGraff Memorial, Medina Memorial, Buffalo General, Millard Suburban and Buffalo & United Memorial (Batavia).