Predictive factors for exacerbation and re-exacerbation in COPD: Results from the Swiss COPD cohort

Background: Acute exacerbations are key events in COPD, associated with a decline in lung function, lower quality of life and increased mortality. Aims and objectives: The Swiss COPD cohort was established to collect spirometric and other data of patients treated in primary care. Our objective was to evaluate different potentially predictive factors for exacerbation and re-exacerbation. Methods: In order to predict exacerbation until the next visit based on the knowledge of exacerbation since the last visit, a multistate model described by Therneau and Grambsch was performed. Results: Data of 748 patients (63% males, 44.1% current smokers) were available for model analysis. Mean FEV1/FVC was 53.1% (±11.5). Hospitalisation for any reason (HR1.7; p0.04) and pronounced dyspnea (HR for mMRC grade 4 3.0; p<0.001) at last visit as well as prescription of short-acting bronchodilators (HR1.7; p<0.001), inhaled (HR1.2; p0.005) or systemic corticosteroids (HR1.8; p0.015) were significantly associated with exacerbation when having had no exacerbation at last visit. Higher FEV1/FVC (HR0.9; p0.008) and higher FEV1 values (HR0.9; p0.001) seemed to be protective. When already having had an exacerbation at last visit, pronounced dyspnea (HR for mMRC grade 4 1.9; p0.026) and cerebrovascular insult (HR2.1; p0.003) were significantly associated with re-exacerbation. Physical activity (HR0.6; p0.031) and treatment with long-acting anticholinergics (HR0.7; p0.044) seemed to play a significant protective role. Conclusion: Our data confirmed well-established risk factors for exacerbations whilst analyzing their predictive association with exacerbation and re-exacerbation with a multistate model approach.