Classification of pressure ulcers

Several systems exist for classifying pressure ulcers, though none of them have been evaluated for interrater reliability. A new grading scale was compared with the commonly used Shea classification. This new scale was developed to provide a more complete description of pressure ulcer healing. The advantages of this scale include a classification of red areas as ulcers to help prevent further deterioration and classification of healed sores to note potential problems. The Yarkony-Kirk scale classifies a red area as a grade 1 ulcer, and involvement of the epidermis and dermis with no subcutaneous fat observed as a grade 2 ulcer. Grade 3 indicates exposed subcutaneous fat with no muscle observed. Exposed muscle without bone involvement is classified as a grade 4 ulcer, and grade 5 describes exposed bone with no joint space involvement. Grade 6 indicates joint space involvement. There is a classification of pressure sore healed to indicate a healed pressure ulcer. Interrater reliability was assessed by two nurses. In spite of an increased number of categories for the Yarkony-Kirk scale, there was no decline in reliability. Reliability was excellent with an interrater correlation of 0.90 for the Yarkony-Kirk scale and 0.86 for the Shea classification when measured for 72 patients. Eighty-five percent of the ratings for the Yarkony-Kirk scale were identical, whereas only 68% were identical for the Shea classification. Three percent of the ratings for the Shea classification were greater than +/- 1 category; 6% of the ratings for the Yarkony-Kirk scale were greater than +/- 1 category. This scale appears to possess good reliability and to describe pressure ulcers more completely. This scale may also be used to teach prevention activities as well as ulcer classification.