Evaluation of validity of the new diabetic foot ulcer assessment scale in Indonesia

We developed a new assessment tool for diabetic foot ulcers because no such tool specifically for diabetic foot ulcer exists. The diabetic foot ulcer assessment scale (DFUAS) has 11 domain items. The minimum and maximum scores on this scale are 0 and 98, respectively; higher scores indicate more severe wounds. The aim of this study was to evaluate the concurrent validity, construct validity and predictive validity of DFUAS in Indonesia. A prospective cohort study was conducted on patients with diabetic foot ulcer at Kitamura wound clinic in Indonesia. A total of 62 patients with 70 diabetic foot ulcers were assessed with DFUAS tool, Bates-Jensen wound assessment tool (BWAT), and pressure ulcer scale for healing (PUSH). Concurrent validity was determined by correlation of the DFUAS total score with the external criterion (BWAT, PUSH, and wound surface area). A comparison between the total DFUAS score and chronic wound status was made to determine construct validity. We also analyzed 41 wounds that were followed for 4 weeks to evaluate predictive validity. The correlation coefficient total scores of the DFUAS against the BWAT, PUSH, and wound surface area were 0.92, 0.87, and 0.82, respectively. The comparison of the total DFUAS score with chronic wound status was p<0.001. The predictive validity test indicated that a DFUAS cutoff score of 12 produced the best balance of sensitivity, specificity, positive predictive value, and negative predictive value (89%, 71%, 86%, and 77%, respectively). In conclusion, the newly developed DFUAS is a valid tool for assessing diabetic foot ulcers.