NPHR, FPR, and PLT as predictors of ulcerative colitis severity: a single-center retrospective study in China

Background Ulcerative colitis (UC) is a chronic inflammatory bowel disease, and precise evaluation of disease activity is essential for effective management. This study aimed to assess the value of the peripheral-blood neutrophil percentage-to-hemoglobin ratio (NPHR), fibrinogen-to-prealbumin ratio (FPR), and platelet count (PLT) in identifying moderate-to-severe UC and to develop a predictive model for clinical risk stratification. Methods Data from 277 hospitalized UC patients, consecutively admitted to the Department of Gastroenterology at the Affiliated Hospital of Jining Medical University between May 2023 and October 2025, were retrospectively analyzed. Disease activity was classified based on the modified Mayo score into low-activity (remission or mild) and moderate-to-severe groups. Independent predictors were identified using multivariable logistic regression and incorporated into a nomogram. Discrimination and calibration were assessed via receiver operating characteristic (ROC) curves and calibration curves, respectively. Clinical utility was evaluated through decision curve analysis (DCA) and the clinical impact curve (CIC). Results NPHR, FPR, and PLT were independent risk factors for moderate-to-severe UC ( p 0.05). The areas under the ROC curves for NPHR, FPR, and PLT were 0.823 (95% CI, 0.773–0.873), 0.788 (95% CI, 0.733–0.842), and 0.746 (95% CI, 0.687–0.805), respectively. The calibration curve demonstrated strong agreement with the ideal line. DCA revealed a favorable net benefit within a threshold probability range of 0.16–1.0, while CIC confirmed the model’s high clinical utility in the range of 0.30–0.90. Conclusion NPHR, FPR, and PLT are independent predictors of moderate-to-severe UC. The combination of these markers enhances predictive accuracy and provides a valuable tool for disease activity assessment.