AECOPD	acute exacerbations of COPD
AECOPD + HF	acute exacerbations of COPD and heart failure
AECOPD + OD	diagnosis other than AECOPD or AECOPD + HF
CRP	C-reactive protein
ED	emergency department
GOLD	Global initiative for Obstructive Lung Disease
HF	Heart failure
ICS	inhaled corticosteroids
LTOT	long-term oxygen therapy
NIV	non-invasive ventilation
NLR	neutrophil-to-lymphocyte ratio
NT-proBNP	N-terminal pro B-type natriuretic peptide
OCS	oral corticosteroids
RW	respiratory ward