FBL and influenza: The model's discrimination, accuracy, clinical utility, and generalizability were evaluated using receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA).<h4>Results</h4>Multivariate analysis showed that influenza season, fibrinogen (Fib) level, fever duration, and C-reactive protein (CRP) were significantly associated with MPP co-infection (p < 0.05).