Exacerbation frequency is central in treatment strategies for chronic obstructive pulmonary disease. However, whether chronic obstructive pulmonary disease patients from the general population with frequent exacerbations continue to have frequent exacerbations over an extended period of time is currently unknown. In this study, we aimed to investigate the stability of the frequent exacerbator in a population-based setting. To this end, we conducted a nationwide register-based descriptive study with a 10-year follow-up period of chronic obstructive pulmonary disease patients with at least one medically treated exacerbation in 2003. Each subsequent year, we divided the population into frequent, infrequent and non-exacerbators and quantified the flow between categories. Further, we estimated the percentage of frequent exacerbators at baseline who stayed in this category each year during a 5-year follow-up. We identified 19,752 patients with chronic obstructive pulmonary disease and an exacerbation in 2003. Thirty percent were frequent exacerbators. Overall, the majority of exacerbators in 2003 were non-exacerbators in the following years (60% in 2004 increasing to 68% in 2012). Approximately half of frequent exacerbators in one year experienced a decrease in exacerbation frequency and had either zero or one exacerbation in the subsequent year. This pattern was stable throughout follow-up. During a 5-year follow-up period, a substantial proportion (42%) of frequent exacerbators in 2003 had no additional years as frequent exacerbators, while the minority (6%) remained in this category each year. In conclusion, the rate of exacerbations shows considerable variation over time among chronic obstructive pulmonary disease patients in the general population. This might hold implications for chronic obstructive pulmonary disease treatment guidelines and their practical application.
Chronic obstructive lung disease: VARIATIONS IN DISEASE PROGRESSION: Patients with chronic obstructive pulmonary disease (COPD) who suffer from frequent exacerbations do not necessarily persist with such severity over time. Exacerbations in COPD are defined by worsening respiratory symptoms that result in changes to treatment, hospitalization and, at worst, death. However, clarity is needed on whether frequent exacerbations is a stable feature of some patients' disease. Mette Reilev at the University of Southern Denmark and co-workers followed, over 10 years, 19,752 COPD patients living in Denmark who suffered at least one exacerbation in 2003. By 2004, 60% of patients were classed as infrequent or non-exacerbators, rising to 68% by 2012. Very few patients remained "frequent exacerbators", suggesting the rate of exacerbations changes considerably over time. This could hold implications for COPD treatment and challenge assumptions made about disease progression.