Development and validation of the Diabetic Foot Ulcer Scale-short form (DFS-SF).
BACKGROUND
The Diabetic Foot Ulcer Scale (DFS) provides comprehensive measurement of the impact of diabetic foot ulcers on patients' QOL through self-administration of 64 items comprising 15 subscales.


OBJECTIVE
To develop and evaluate a short form of the DFS (DFS-SF) to reduce patient burden and the number of outcome measures, and to improve sensitivity to change in clinical condition.


METHODS
The DFS-SF was created through the analysis of data from a double-blind, placebo-controlled, randomised trial of the efficacy and safety of becaplermin (recombinant human platelet-derived growth factor BB) in the treatment of chronic, full-thickness, neuropathic, diabetic foot ulcers. Using these data, items demonstrating poor psychometric properties were eliminated. Exploratory factor analyses were then conducted to develop a new, more parsimonious scaling algorithm that optimised the internal consistency of the new subscales. Finally, data from two additional clinical trials were used to assess replicability of the DFS-SF subscale structure.


RESULTS
The DFS-SF contains a total of 29 items comprising six subscales. The results of both confirmatory and exploratory factor analyses provided support for the scaling algorithm. The DFS-SF subscales showed good internal consistency, reliability and construct validity, and demonstrated sensitivity to ulcer healing.


CONCLUSIONS
The results of this investigation indicate that the DFS-SF has good psychometric properties and replicability.
Statistics Research Division, RTI International, Research Triangle Park, North Carolina 27709-2194, USA. cmb@rti.org
Carla M
CM
Bann
Sheri E
SE
Fehnel
Dennis D
DD
Gagnon
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017719:Diabetic Foot / Q000523:psychology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics / Q000379:methods; D011788:Quality of Life / Q000523:psychology; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D018434:Sickness Impact Profile