Validity of DMIST for monitoring healing of diabetic foot ulcers

A new diabetic foot evaluation scale was proposed, using the seven domains of depth, maceration, inflammation/infection, size, tissue type of the wound bed, type of wound edge, and tunneling/undermining. This scale was named "DMIST" as an acronym from the initials of the domains. The purpose of this study was to evaluate the validity of DMIST. Secondary analysis was conducted in three investigations performed using the diabetic foot ulcer assessment scale (DFUAS) in Japan and Indonesia. Secondary analysis was assessed using DMIST, PUSH, and DESIGN for 4 weeks based on DFUAS score and photographs of diabetic foot ulcers by researchers. Concurrent validity was determined from the correlation of total DMIST scores with PUSH and DESIGN scores. Construct validity was determined by comparisons between total DMIST score and grade of the Wagner classification. Predictive validity was determined by receiver operating characteristic curve analysis for wound non-healing 4 weeks later. Subjects comprised 35 Japanese patients and 118 Indonesian patients. Correlations of total DMIST score with PUSH and DESIGN scores were 0.831 and 0.822, respectively. Comparison of total DMIST scores with grade of the Wagner classification (Grade I vs. Grade II/III vs. Grade IV/V) was p < 0.001. Based on an area under the curve of 0.872, a DMIST score of 9 was selected as a cut-off, offering sensitivity of 0.855 and specificity of 0.786 for wound non-healing 4 weeks later. Our findings suggest that DMIST offers high validity.