Unsuspected risk factors of frequent exacerbations requiring hospital admission in chronic obstructive pulmonary disease

Introduction Severe exacerbations are the leading cause of fatal events in chronic obstructive pulmonary disease (COPD). The new Global Initiative for Chronic Obstructive Lung Disease strategy included the number of exacerbations in the grading of the disease. The primary aim of this study was to evaluate the potentially modifiable precipitating factors of frequent severe exacerbations requiring hospital admission in COPD. The secondary aim was to investigate the risk factors of readmission within 2months following an exacerbation requiring hospitalisation. Methods Data regarding the number of exacerbations in the previous year, current comorbidities, medications, and clinical and functional status of COPD patients were evaluated. Results We included 107 COPD patients (85% men). The mean number of severe exacerbations was 1.3 +/- 1.7 (per patient/per year), and 37.4% of the patients had frequent severe exacerbations (2/year). Multivariate analysis indicated that haematocrit <41%, angiotensin converting enzyme inhibitor or angiotensin receptor blocker use, positive gastro-oesophageal reflux disease symptoms, poor adherence to inhaled therapy/regular outpatient follow-up visits and FEV1 <50% were independent predictors of frequent severe exacerbations. Readmission rate within 2months after hospital discharge was 39.3%. The independent risk factors of readmission were poor adherence to inhaled therapy/regular outpatient follow-up visits, serum haematocrit <41%, and FEV1 <50%. Conclusion Chronic obstructive pulmonary disease patients with frequent exacerbations should be carefully assessed for modifiable confounding risk factors regardless of poor lung function to decrease exacerbation frequency and related poor prognosis.