Development and validation of the experimental wound assessment tool (EWAT) for pressure ulcer in laboratory animals

Introduction: In studies with experimental models of pressure ulcer, until date, there is no validated instrument to assess the various visual aspects of the healing process. Measure of wound area is the most used method for this purpose. Thus, we aimed to develop and validate a visual assessment tool for the evaluation of healing in experimental models of pressure ulcer. Methods: The Experimental Wound Assessment Tool (EWAT) was developed based on tools used in clinical practice. The tool was validated using 50 photographs of wound induced by a noninvasive pressure ulcer model in Swiss mice. Five judges performed the Content Validity and 3 raters evaluated the photos by EWAT. Items with the Content Validity Index score lower than 0.8 were modified in accordance to the suggestions of the judges. Results: The EWAT showed moderate to high reliability, whilst the Concurrent Validity Test obtained good to high results, demonstrating a significantly strong positive correlation between the analyses of the raters. Moreover, it was shown to have high correlation with the clinical Photographic Wound Assessment Tool. Discussion: EWAT showed good/excellent results in all the validation tests, showing it to be a good tool to evaluate wound healing process in animal models of pressure ulcer and being recommended for assessment of wound healing in small experimental animals.