Validity and reliability of the Greek version of the Diabetic Foot Ulcer Scale - Short Form (DFS-SF)

OBJECTIVE: Diabetic foot ulcer is a critical and costly complication of diabetes mellitus. The aim of this study was to assess the psychometric properties of the Greek version of the diabetic foot ulcer scale - short form (DFS-SF). DESIGN: A sample of patients with diabetic foot ulcer (N=110) was surveyed with the DFS-SF and various demographic and disease-related questions. The validated Greek SF-36 instrument was used as a "gold standard" for health-related quality of life comparisons. Hypothesized scale structure, internal consistency reliability (Cronbach's alpha) and various forms of construct validity (convergent, discriminative, concurrent and known-groups) were assessed. RESULTS: Multitrait scaling confirmed the scale structure of the DFS-SF, with 32 excellent item convergence (100%) and good discrimination (84.1%) rates. Cronbach's alpha was >0.70 for all scales. Spearman's correlations between similar DFS-SF and SF-36 scales ranged between 0.39-0.79 (p<0.001). Expected interscale correlations and known-groups comparisons supported construct validity. CONCLUSIONS: The observed psychometric properties of the Greek DFS-SF imply suitability for assessing health-related quality of life in patients with diabetic foot ulcer. Future studies should focus on generalizability of the results, as well as on specific issues such as longitudinal validity and responsiveness.