Prospective observational study evaluating the predictive value of ankle branchial pressure index on the outcomes of diabetic foot ulcers

Abstract

Background: The study was conducted to determine the diagnostic accuracy of ankle branchial pressure index (ABPI) in predicting major amputation and duration of wound healing in diabetic foot ulcers.Methods: 105 participants (30-85 years) admitted in general surgery inpatient with diabetic foot ulcers during 18 months were enrolled in the present prospective observational study. Institutional ethics committee approved the study and written informed consent was obtained from all study participants. Data was analyzed using R and the tests of significance were chi square test and ANOVA. Area under curve (AUC) of receiver operator characteristic (ROC) was used to describe the diagnostic accuracy of ABPI. P<0.05 was considered statistically significant.Results: The mean ABPI of study participants was 0.7 with 23.8% participants having normal ABPI. Lower ABPI was associated with longer duration of ulcer healing (p=0.003). All participants with ABPI <0.3 required more than 120 days for wound healing (p<0.001) and required above knee amputation (p<0.001). AUC ROC of ABPI and major amputation is 0.987 with 92.9% sensitivity and 98.9% specificity. Significantly higher proportion of participants with ABPI ≤0.48 underwent major amputation. The AUC of ROC of ABPI on duration of wound healing was 0.953 with 84.9% sensitivity and 98.1% specificity. Conclusions: ABPI can be used as a routine tool in all patients with diabetic foot ulcers for screening peripheral arterial disease so that the decision for amputation can be made early during diabetic foot ulcers.