Exacerbation history and blood eosinophil count prior to diagnosis of COPD and risk of subsequent exacerbations.

Background: Prior exacerbation history is used to guide initial maintenance therapy in COPD; however, the recommendations were derived from patients already diagnosed and treated.

Methods: We assessed the rates of moderate (i.e. treated with antibiotics and/or systemic corticosteroids) and severe (i.e. hospitalised) exacerbations in the year following diagnosis in patients newly diagnosed with COPD according to their prior history of exacerbations, blood eosinophil count (BEC) and whether maintenance therapy was started. Data were extracted from the Optimum Patient Care Research Database.

Results: 73 189 patients were included. 61.9% had no exacerbations prior to diagnosis, 21.5% had 1 moderate, 16.5% had ≥2 moderate and 0.3% had ≥1 severe. 50% were started on maintenance therapy. In patients not started on maintenance therapy the rates of moderate exacerbations in the year after diagnosis in patients with no, 1 moderate, ≥2 moderate and ≥1 severe prior exacerbations were 0.34 (95% CI 0.33-0.35), 0.59 (95% CI 0.56-0.61), 1.18 (95% CI 1.14-1.23) and 1.21 (95% CI 0.73-1.69), respectively. Similar results were seen in patients started on maintenance therapy. BEC did not add significantly to the prediction of future exacerbation risk.

Conclusions: A single moderate exacerbation in the year prior to diagnosis increases the risk of subsequent exacerbations, and more frequent or severe exacerbations prior to diagnosis are associated with a higher risk.