Prognostic value of shock index, modified shock index, and age shock index in emergency department patients with hemoptysis

Abstract

Hemoptysis is a challenging respiratory emergency ranging from mild symptoms to life-threatening conditions. Early identification of patients at risk for hemodynamic collapse and massive bleeding is crucial for guiding admission to respiratory wards or intensive care units. This study aimed to assess the prognostic performance of the shock index (SI), modified shock index (MSI), and age shock index (ASI) in predicting 30-day mortality and life-threatening hemoptysis (LTH). We conducted a retrospective cohort study including adult patients admitted to the ED with hemoptysis. SI, MSI, and ASI were calculated using initial vital signs. The primary outcome was 30-day mortality; the secondary outcome was LTH. To evaluate predictive performance, we performed multivariable logistic regression, receiver operating characteristic (ROC) analysis, continuous net reclassification improvement (NRI), integrated discrimination improvement (IDI), and Cox proportional hazards models. Exploratory LASSO regression was used only for preliminary screening of candidate variables. Among 592 patients, the 30-day mortality rate was 8.4%. All three indices demonstrated significant discrimination for mortality (AUCs: 0.854 for ASI, 0.836 for SI, 0.819 for MSI). ASI achieved the highest IDI (0.057) and NRI (0.943) improvement over the base model. In Cox regression, a 1-SD increase in the ASI was associated with a higher hazard of mortality (HR: 1.813; 95% CI: 1.449–2.268) and the highest model concordance (C-index: 0.870). Kaplan–Meier analysis confirmed significantly lower survival in high-risk groups (log-rank p < 0.001 for all indices). For the secondary outcome (LTH), simple hemodynamic indices (SI and MSI) outperformed ASI, which was not an independent predictor in multivariable analysis. Each index demonstrates a distinct prognostic strength in the management of hemoptysis. The ASI may have utility for initial triage risk assessment due to its association with 30-day mortality, whereas the MSI and the SI appear more reflective of acute hemodynamic crises such as LTH. These findings suggest that a tailored application of shock indices may contribute to improved risk stratification in hemoptysis management; however, this potential two-tiered approach warrants further prospective validation.