Statistical methods
REGRESSION
All statistical analyses were conducted using SPSS 26.0 (IBM, Armonk, NY, USA). Using SPSS, patients were divided into a model group and a validation group in a 7:3 ratio. Measurement data that followed a normal distribution were expressed as the mean ± standard deviation (x ± s) and compared between groups using the Spearman’s rank correlation analysis was employed to investigate the correlation between various risk factors and patient mortality, and logistic regression analysis was used to identify the key risk factors associated with worsening conditions in patients with BPS/IC. The results of these analyses formed the basis for the construction of the nomogram, the performance of which was then evaluated by calculating the AUC, or area under the receiver operating characteristic (ROC) curve. Additionally, the net clinical benefit and effectiveness of the nomogram were assessed using decision curve analysis (DCA). All statistical tests were two-tailed, and a 