Chronic obstructive pulmonary disease (COPD) patients experiencing several episodes of acute clinical derangement suffer from increased morbidity, mortality, and accelerated decline in lung function. Nevertheless, the relationship between co-morbidity profile and exacerbation rates in the frequent exacerbator phenotype is poorly characterized, and evidence-based management guidelines are lacking. We sought to evaluate the co-morbidity profile and treatment patterns of "frequent exacerbators" with severe or very severe airflow limitation. We conducted a cross-sectional, multicenter study in 50 Italian hospitals. Pulmonologists abstracted clinical information from medical charts of 743 COPD frequent exacerbators. We evaluated the exacerbation risk and center-related variations in diagnostic testing. One-third of patients (n = 210) underwent a bronchodilator response test, and 163 (22%) received a computerized tomography (CT) scan; 35 had a partial response to bronchodilators, while 119 had a diagnosis of emphysema; 584 (79%) lacked sufficient diagnostic testing for classification. Only 17% of patients did not have any coexistent disease. Cardiovascular conditions were the most frequent co-morbidities. A history of heart failure [odds ratio (OR): 1.89; 95% confidence interval (CI) 1.48-2.3] and affective disorders (OR: 1.66; 95% CI 1.24-2.1) was associated with the frequency of exacerbations. Center membership was strongly associated with exacerbation risk, independent of casemix (variance partition coefficient = 29.6%). Examining the regional variation in health outcomes and health care behavior may help identify the best practices, especially when evidence-based recommendations are lacking and uncertainties surround clinical decision-making.
Keywords: COPD; Coexistent diseases; epidemiology; frequent exacerbator phenotype; treatment pattern.