Validation and implementation of the FLHASc score for risk stratification of patients with hemoptysis in the emergency department

Background: Hemoptysis is a potentially life-threatening symptom that often prompts emergency department (ED) evaluation and hospitalization. Reliable prognostic tools to guide clinical decision-making and optimize resource use are currently lacking. Objective: To prospectively validate the Florence Hemoptysis Assessment Score (FLHASc) in patients presenting with hemoptysis to the ED, and to eventually derive and validate an improved version of the score (FLHASc2). Methods: We analyzed data from the POPEIHE study (NCT06067997), a multicenter prospective cohort of 546 consecutive adult patients presenting with hemoptysis to 9 Italian EDs. The primary outcome was a composite of in-hospital death, need for ventilatory support, intensive care unit (ICU) admission, blood transfusion, or invasive hemostatic procedures. We evaluated the prognostic performance of the original FLHASc, then derived a new model (FLHASc2) using multivariate logistic regression in a randomly selected derivation cohort (n = 321) and validated it in the remaining cohort (n = 225). A simplified version of the score was also tested. Results: The original FLHASc demonstrated moderate discriminatory ability (AUC 0.71; 95% CI: 0.65–0.76) and suboptimal calibration. The FLHASc2 showed improved performance (AUC 0.79, 95% CI: 0.73–0.87 in derivation and 0.81, 95% CI: 0.73–0.88, in validation cohorts; Brier score < 0.10 in both). The simplified FLHASc2 (sFLHASc2), assigning one point per variable, maintained comparable accuracy (AUC 0.80, 95% CI: 0.72–0.87) and identified 47.8% of patients as low risk (2.7% event rate). When combined with a negative chest X-ray, the observed event rate in this subgroup dropped to 0.87%, with a negative predictive value of 99.1% (CI 95%, 96.5–100%). Conclusions: The FLHASc2 and its simplified version are accurate prognostic tools for identifying hemoptysis patients at low risk of short-term adverse outcomes. Use of the sFLHASc2 combined with chest X-ray may allow safe ED discharge in nearly half of cases. A prospective management trial is warranted to confirm its clinical impact. Trial registration number: NCT06067997