CALCA and Acute bronchitis: In patients with acute bronchitis (AUC: 0.91 (95% CI: 0.88, 0.95), adjusted OR: 1.97 (95% CI: 0.20, 19.52), P = 0.561) and ECOPD (AUC: 0.79 (95% CI: 0.69, 0.90), adjusted OR: 6.12 (95% CI: 2.46, 15.18), P <0.001), admission PCT levels were good predictors to identify patients at risk for mortality.