# Development and evaluation of a nomogram model for predicting prolonged hospitalization after spinal tuberculosis focus decompression, fusion, and internal fixation surgery

## TL;DR

This study developed a nomogram to predict prolonged hospitalization after spinal tuberculosis surgery, using factors like age, extra-spinal TB, and preoperative health scores.

## Contribution

A novel nomogram model was developed and validated for predicting prolonged hospitalization after spinal TB surgery.

## Key findings

- Advanced age, extra-spinal TB, and higher preoperative ASA scores were significant predictors of prolonged hospitalization.
- The nomogram showed good discrimination (AUC 0.771) and calibration (C index 0.787) in predicting hospitalization duration.
- Decision curve analysis confirmed the clinical utility of the nomogram for preoperative risk assessment.

## Abstract

Spinal tuberculosis remains a significant clinical challenge in high-prevalence regions. Despite advances in medical treatment, surgical interventions, such as debridement, decompression, and fusion, are often required, but their complexity increases perioperative morbidity and prolongs hospitalization. Identifying preoperative predictors of extended hospital stay may improve patient management and resource allocation.

In this retrospective study, 256 patients with confirmed spinal tuberculosis who were treated between January 2021 and December 2024 were included. Prolonged hospitalization was defined as a postoperative stay > 21 days. Univariate and multivariate logistic regression analyses were performed, and significant predictors were integrated into a nomogram. Model performance was evaluated by receiver operating characteristic (ROC) analysis, calibration plots with bootstrap resampling, and decision curve analysis (DCA).

The patients were divided into a modeling group (n = 170) and a validation group (n = 86). Baseline characteristics were comparable between groups. Multivariate analysis identified increasing age (OR 1.042, 95% CI 1.013–1.071, P = 0.005), concomitant TB at other sites (OR 2.875, 95% CI 1.168–7.100, P = 0.022), and a higher preoperative American Society of Anesthesiologists score (OR 1.537, 95% CI 1.010–2.340, P = 0.046) as independent predictors of prolonged hospitalization. The nomogram demonstrated good discriminative ability (AUC: 0.771 and 0.718) and satisfactory calibration (corrected C index 0.787; Hosmer–Lemeshow P = 0.895). DCA confirmed its clinical utility.

Advanced age, extra-spinal TB involvement, and elevated preoperative ASA score are significant predictors of prolonged hospitalization after spinal TB surgery. The developed nomogram is a practical tool for preoperative risk assessment, warranting further prospective multicenter validation.

The online version contains supplementary material available at 10.1186/s40001-025-03805-8.