Validity of pressure ulcer diagnosis using digital photography

The purpose of this study was to evaluate the validity of digital photographs for the assessment of the presence of pressure ulcers stage 2 or higher. Participants were 48 patients (28 white and 20 black) with pressure ulcers identified in the course of a wound specialist's routine clinical practice at the University of Maryland Medical Center. One pressure ulcer and one unaffected skin area were photographed on each participating patient. The gold standard diagnosis (stage 2 pressure ulcer vs. stage 1 or no pressure ulcer) was recorded by the wound specialist based on bedside examination. The photographs were reviewed blindly by another wound expert. The sensitivity of the blinded assessment was 97% (95% confidence interval [CI] 91-100%). The specificity was 97% (95% CI 92-100%). The sensitivity and specificity were both 100% in the white patients. In black patients, the sensitivity and specificity were 92% (95% CI 75-100%) and 93% (95% CI 82-100%), respectively. These results suggest that the use of photographic images to assess the presence or absence of a pressure ulcer stage 2 or higher has a high degree of validity. Since blinded outcome assessment is one of the cornerstones of good clinical trial design, photography offers the potential to strengthen future studies.