Reliability of AOFAS Diabetic Foot Questionnaire in Charcot Arthropathy: Stability, Internal Consistency, and Measurable Difference

Abstract

Background: The development of Charcot changes is known to be associated with a high rate of recurrent ulceration and amputation. Unfortunately, the effect of Charcot arthropathy on quality of life in diabetic patients has not been systematically studied because of a lack of a disease-specific instrument. The purpose of this study was to develop and test an instrument to evaluate the health-related quality of life of diabetic foot disease. Methods: Subjects diagnosed with Charcot arthropathy completed a patient self-administered questionnaire, and clinicians completed an accompanying observational survey. The patient self-administered questionnaire was organized into five general sections: demographics, general health, diabetes-related symptoms, comorbidities, and satisfaction. The scales measured the effect in six health domains: 1) general health, 2) care, 3) worry, 4) sleep, 5) emotion, and 6) physicality. The psychometric properties of the scales were evaluated and the summary scores for the Short-Form Health Survey (SF-36) were compared to published norms for other major medical illnesses. Results: Of the 89 enrolled patients, 57 who completed the questionnaire on enrollment returned a second completed form at 3-month followup. Over the 3-month followup period most of the patients showed an improvement in the Eichenholtz staging. The internal consistency of most was moderate to high and, in general, the scale scores were stable over 3 months. However, several of the scales suffered from low-ceiling or high-floor effects. Patients with Charcot arthropathy had a much lower physical component score on enrollment than the reported norms for other disease conditions, including diabetes. Conclusions: Quality of life represents an important set of outcomes when evaluating the effectiveness of treatment for patients with Charcot arthropathy. This study represents an initial attempt to develop a standardized survey for use with this patient population. Further studies need to be done with larger groups of patients to refine the tool and to begin the validation process. The instrument developed could be used for comparing treatment strategies for Charcot arthropathy.