Relationship between exacerbation frequency and lung function decline in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterised by both an accelerated decline in lung function and periods of acute deterioration in symptoms termed exacerbations. The aim of this study was to investigate whether these are related.

Over 4 years, peak expiratory flow (PEF) and symptoms were measured at home daily by 109 patients with COPD (81 men; median (IQR) age 68.1 (63-74) years; arterial oxygen tension (PaO(2)) 9.00 (8.3-9.5) kPa, forced expiratory volume in 1 second (FEV(1)) 1.00 (0.7-1.3) l, forced vital capacity (FVC) 2.51 (1.9-3.0) l); of these, 32 (29 men) recorded daily FEV(1). Exacerbations were identified from symptoms and the effect of frequent or infrequent exacerbations (> or