ObjectivesTo explore a reliable and simple predictive tool for 30-day mortality of influenza A community-acquired pneumonia (CAP).MethodsA multicenter retrospective study was conducted on 178 patients hospitalized with influenza A CAP, including 144 alive patients and 34 dead patients. Receiver operating characteristic (ROC) curves were performed to verify the accuracy of severity scores as 30-day mortality predictors in the study patients.ResultsThe 30-day mortality of influenza A CAP was 19.1%. The actual mortality of PSI risk class Ⅰ-Ⅱ and CURB-65 score 0-1 were 14.5% and 15.7%, respectively, which were much higher than the predicted mortality. Logistic regression confirmed blood urea nitrogen >7 mmol/L (U), albumin <35 g/L (A) and peripheral blood lymphocyte count <0.7×10 9/L (L) were independent risk factors for 30-day mortality of influenza A CAP. The area under the ROC curve (AUC) of UAL (blood urea nitrogen >7 mmol/L+ albumin <35 g/L+ peripheral blood lymphocyte count <0.7×10 9/L) was 0.891, which was higher than CURB-65 score (AUC=0.777, P=0.008 3), CRB-65 score (AUC=0.590, P<0.000 1), and PSI risk class (AUC=0.568,P=0.000 1).ConclusionUAL is a reliable and simple predictive tool for 30-day mortality of influenza A CAP.