Fig. 2

(A). Antibiotic therapy use defined as efficacy Endpoint and (B). 28-day mortality defined as safety endpoint. Abbreviations: AECOPD, acute exacerbation of chronic obstructive pulmonary disease; ARI, acute respiratory infection; CI, confidence interval; N/A, not applicable; OR, odds ratio; PCT, procalcitonin; SD, standard deviation; PCT, procalcitonin