Development and internal validation of a nomogram for predicting 30-day mortality in older patients with hemophagocytic lymphohistiocytosis

OBJECTIVE: To develop and validate a prognostic model for predicting 30-day mortality in older patients with hemophagocytic lymphohistiocytosis (HLH). METHODS: This retrospective cohort study enrolled 204 HLH patients aged ≥ 65 years from January 2015 to November 2023. We divided the cohort into development and validation cohorts in a 7:3 ratio. Then we used logistic regression analysis and the least absolute shrinkage and selection operator regression (LASSO) to develop a prognostic model. Performance was assessed using the area under the receiver operating characteristic curve (AUC) and decision curve analysis (DCA). RESULTS: The 30-day mortality rate was 40.7%. Multivariate analysis identified five risk factors independently associated with 30-day mortality of older patients with HLH: Age, platelet (PLT), alanine aminotransferase (ALT), UREA, and ferritin. The model has good discrimination and calibration ability (AUC: 0.828 (0.755-0.886) for the development cohort and 0.773 (0.654-0.891) for the validation cohort). The model showed excellent calibration and clinical utility. Kaplan-Meier survival curve analysis showed that patients with the nomogram value > 0.3851 were positively correlated with higher 30-day mortality (P < 0.001). CONCLUSION: The model incorporating age and four routine clinical parameters accurately stratifies 30-day mortality risk in older HLH patients demonstrating strong discriminative ability and clinical applicability, thereby providing a basis for clinical decision-making.