The long-term clinical impact of COPD exacerbations: a 3-year observational study (SHERLOCK)

BACKGROUND AND AIMS: Exacerbations of chronic obstructive pulmonary disease (COPD) drive disease progression and can lead to an accelerated decline in lung function and a burden on healthcare systems. The retrospective, observational cohort Study on HEalthcare Resource utiLization related to exacerbatiOns in patients with COPD (SHERLOCK; D5980R00014) evaluated the associations between exacerbation history and rates of subsequent COPD exacerbations in primary care patients from the National Health Service in Greater Glasgow and Clyde, United Kingdom. METHODS: Patients were stratified into four groups according to exacerbation history in the year before the index date: Group A (no exacerbations), Group B (1 moderate exacerbation only), Group C (1 severe exacerbation only), and Group D (⩾2 moderate or severe exacerbations). The frequencies of moderate and/or severe exacerbations were recorded over 36 months of follow-up and compared with reference Group A, using generalized linear models. RESULTS: Over 36 months of follow-up, the adjusted rate ratios (RRs, 95% confidence interval) of moderate or severe exacerbations relative to Group A were 1.60 (1.53, 1.67), 1.75 (1.50, 2.04), 1.61 (1.54, 1.68), and 3.61 (3.48, 3.74) for Groups B, C, B + C, and D, respectively. Compared with Group A, patients in Group C exhibited an increased rate of moderate (RR, 1.58 (1.35, 1.85)) and severe exacerbations (RR, 3.13 (2.20, 4.46)). CONCLUSION: SHERLOCK highlights that even one moderate exacerbation increases the risk for subsequent exacerbations compared with having no recent prior exacerbations. Reviewing recent exacerbation history to ascertain future exacerbation risk and inform COPD management may reduce hospitalizations and improve patient outcomes.