Predictors of amputation in patients with diabetic foot ulcers: a multi-centre retrospective cohort study

Investigating risk factors for amputation in patients with diabetic foot ulcer (DFU) and developing a nomogram prediction model.

We gathered case data of DFU patients from five medical institutions in Anhui Province, China. Following eligibility criteria, a retrospective case-control study was performed on data from 526 patients.

Among the 526 patients (mean age: 63.32 ± 12.14), 179 were female, and 347 were male; 264 underwent amputation. Univariate analysis identified several predictors for amputation, including Blood type-B, Ambulation, history of amputation (Hx. Of amputation), Bacterial culture-positive, Wagner grade, peripheral arterial disease (PAD), and laboratory parameters (HbA1c, Hb, CRP, ALB, FIB, PLT, Protein). In the multivariate regression, six variables emerged as independent predictors: Blood type-B (OR = 2.332, 95%CI [1.488–3.657], p < 0.001), Hx. Of amputation (2.298 [1.348–3.917], p = 0.002), Bacterial culture-positive (2.490 [1.618–3.830], p <0.001), Wagner 3 (1.787 [1.049–3.046], p = 0.033), Wagner 4–5 (4.272 [2.444–7.468], p <0.001), PAD (1.554 [1.030–2.345], p = 0.036). We developed a nomogram prediction model utilizing the aforementioned independent risk factors. The model demonstrated a favorable predictive ability for amputation risk, as evidenced by its area under the receiver operating characteristics (ROC) curve of 0.756 and the well-fitted corrected nomogram calibration curve.

Our findings underscore Blood type-B, Hx. Of amputation, Bacterial culture-positive, Wagner 3–5, and PAD as independent risk factors for amputation in DFU patients. The resultant nomogram exhibits substantial accuracy in predicting amputation occurrence. Timely identification of these risk factors can reduce DFU-related amputation rates.