Development of the DESIGN-R with an observational study: An absolute evaluation tool for monitoring pressure ulcer wound healing

DESIGN is a seven-item (depth, exudates, size, inflammation/infection, granulation, necrosis, and pocket) monitoring scale for pressure ulcers developed in 2002 by the scientific education committee of the Japanese Society of Pressure Ulcers. DESIGN is a very useful tool for chronological monitoring of each pressure ulcer, but a key limitation of this tool is its inability to compare the wound-healing process among different pressure ulcers in different patients due to a lack of statistical item weighting. Our aim was to weight DESIGN items by statistical analysis and develop a new validated tool to overcome this limitation. Subjects comprised 3,601 patients with pressure ulcers. Patients were followed every week during the study period. To establish the weighting of each item and grade, we estimated the probabilities of wound healing at 12-month follow-up using multivariable Cox's regression analysis. Weighting (-β value) for each item in order of the highest rank was: pocket, 2.289; size, 1.573; inflammation/infection, 0.778; granulation tissue, 0.682; exudate, 0.543; and necrotic tissue, 0.529. Based on these findings, a new, validated "DESIGN-Rating tool" for monitoring the progression of pressure ulcer healing was developed, implying the development of an absolute evaluation tool and clinical indicator to assess the quality of medical care.