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

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. 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). 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. 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%). 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 • We prospectively validated the FLHASc score in a large multicenter ED cohort • A new prognostic model (FLHASc2), integrating respiratory failure, smoking, and bronchiectasis, demonstrated significantly improved accuracy and robust calibration in both derivation and validation cohorts. • The simplified FLHASc2 (one point per variable) preserved prognostic performance, accurately identifying nearly 50% of hemoptysis patients as low-risk for major adverse events. • Combining sFLHASc2 with a negative chest X-ray further refined risk stratification, defining a very-low-risk group with an adverse event rate of only 0.87% (NPV 99%). • The sFLHASc2 may support safe ED discharge and more efficient use of diagnostic resources; a prospective management trial is warranted to assess real-world clinical impact.