Analysis of clinical characteristics in patients with diabetic foot ulcers undergoing amputation and establishment of a nomogram prediction model

Abstract

To assess the accuracy of a nomogram for predicting the risk of lower-extremity amputation (LEA) in individuals with diabetic foot ulcers (DFUs). We retrospectively analyzed data from 144 patients with DFUs at the Department of Orthopedics of the First Affiliated Hospital of Nanchang University, collected between January 2020 and December 2023. Univariate analysis determined primary predictive factors for amputation, followed by single and multifactor logistic regression analyses to indentify independent factors. These were utilized to develop a prediction model using R4.3.3, and a nomogram was created. Its performance was verified using receiver operating characteristic (ROC), corrected calibration, and clinical decision curves. Twelve primary predictive factors were identified from 20 variables, including age, Wagner grades, peripheral angiopathy of diabetes (PAD), chronic kidney disease(CKD), C-reactive protein(CRP) and the number of blood sugar abnormalities(BSA) etc. Multivariate logical regression analysis illustrated that Wagner grades, PAD, CRP, CKD, and the number of BSA were independent risk factors. The area under the curve (AUC) of the ROC curve was 0.967, and the revised calibration curve of the nomogram demonstrated strong fitting ability. This prediction model is a valuable tool for screening LEA risk and preventing DFU from progressing into amputation.