NPPB and chronic obstructive pulmonary disease: FVC: forced vital capacity; FEV1: forced expiratory volume in 1 s; mMRC: modified Medical Research Council; CAT: COPD Assessment Test; TB: tuberculosis; AE: Acute Exacerbation; AECOPD: Acute Exacerbation of Chronic Obstructive Pulmonary Disease; CRP:C-reactive protein; PCT: Procalcitonin; BNP: brain natriuretic peptide; PaO2: partial pressure of oxygen in artery; PaCO2: partial pressure of carbon dioxide in arterial blood; SaO2: oxygen saturation in arterial blood; ICS: inhaled corticosteroids