Development and validation of a nomogram for predicting postoperative new-onset constipation in elderly patients undergoing hip fracture surgery

Postoperative constipation is often accompanied by abdominal pain, loss of appetite, nausea and vomiting, or even adverse cardiovascular and cerebrovascular events. This study aimed to establish nomogram for predicting the risk of postoperative new-onset constipation in elderly patients with hip fractures, and validate its performance. Patients who underwent hip surgery in our hospital between January 2021 and December 2023 were enrolled in this study. Univariate and multivariate logistic regression analyses were performed to identify significant factors influencing postoperative constipation. A nomogram was constructed for predicting postoperative new-onset constipation, and its discriminative, concordance, and clinical utility were examined. A total of 1,092 elderly patients were enrolled, among whom 955 without preoperative constipation were included for nomogram establishment. Multivariable logistic regression identified ten factors were associated with postoperative new-onset constipation, including body mass index, cerebrovascular disease, cardiovascular disease, gastrointestinal disease, blood loss, renal disease, preoperative lower limb thrombosis, heart surgery history, patient-controlled analgesia and preoperative pulmonary infection. A nomogram comprising these factors was constructed, and the area under the receiver operating characteristic curve for the training set and the test set were 0.730 (0.692-0.768) and 0.712 (0.651-0.772), respectively. The nomogram developed in this study showed good discriminative ability in predicting the risk of postoperative new-onset constipation in elderly patients undergoing hip fracture surgery. The proposed model is expected to facilitate early identification of high-risk patients and enable timely intervention.