Patterns and characterization of COPD exacerbations using real-time data collection

Abstract

IntroductionPatients with chronic obstructive pulmonary disease often experience exacerbations. These events are important as they are a major cause of morbidity and mortality. Recently, it has been increasingly recognized that patients may experience symptoms suggestive of an exacerbation but do not seek treatment, which are referred to as unreported or untreated exacerbations. Symptom diaries used in clinical trials have the benefit of identifying both treated and untreated exacerbation events.MethodsThe Kamada study was a multicenter, double-blind randomized controlled trial of inhaled augmentation therapy in alpha-1 antitrypsin deficiency (AATD). A retrospective review of daily electronic symptom diary cards was undertaken from the two leading centers to identify symptomatic episodes consistent with a definition of an exacerbation. The aims were to explore the relationship between exacerbation events and classical “Anthonisen” symptoms and to characterize treated and untreated episodes.ResultsForty-six AATD patients with airflow obstruction and history of exacerbations were included in the analysis. Two hundred thirty-three exacerbation episodes were identified: 103 untreated and 130 treated. Untreated episodes were significantly shorter (median 6 days; interquartile range [IQR] 3–10 days) than the treated episodes (median 10 days; IQR 5–18.25 days: P<0.001). Using logistic regression analysis, Anthonisen type and length of dyspnea were significant predictors of the treatment of an exacerbation event.ConclusionReal-time electronic diary cards provide valuable information about the characterization of exacerbations. Untreated episodes are common and are significantly shorter in duration than the treated episodes. Dyspnea is the most important single Anthonisen symptom in the prediction and/or driver of treatment.

<p>Inflammation and infections in unreported chronic obstructive pulmonary disease exacerbations</p>

“…Underreporting of exacerbations by COPD patients was first documented in 1998 by the East London COPD study in which 50.5% of episodes in which subjects recorded symptoms of an exacerbation that were retrospectively identified from symptom diaries, were not reported to the investigators at the time they occurred 3. Similar results have been reported from the same group7 and other groups have found that between 44–82% of exacerbations are unreported 4–6,8,10,11. As identification of unreported exacerbations is retrospective, no clinical samples collected at the time of exacerbation are available so it is not known whether underreporting of exacerbations relates to differences in aetiology or inflammatory responses.…”

“…It is unclear whether unreported exacerbations are simply less severe exacerbations. In some studies symptoms are less severe compared with reported exacerbations,4,5,9,11 whereas others have found no differences in severity of symptoms or physiological parameters between reported and unreported exacerbations 3,6–8. However unreported exacerbations do have long-term significance as they are associated with impaired health status in COPD patients 6,12.…”

Prevalence and associated factors of COPD among Aboriginal peoples in Canada: a cross-sectional study

“…Chronic lower respiratory disease (the majority consisting of COPD) is the fourth leading cause of death in Canada 6. Furthermore, COPD is the most common cause of chronic disease hospitalization in Canada 7.…”

<p>Improving the Lives of Patients with Alpha-1 Antitrypsin Deficiency</p>

“…Exacerbations are characterized by increased dyspnea, increased sputum volume and new or increased sputum purulence. Of note, while patients with AATD more frequently seek treatment for dyspnea and sputum volume during disease exacerbations, 28 patients are less worried about any changes in sputum color. However, sputum color is a more reliable indicator of bacterial infection requiring antibiotic treatment and the associated increase in sputum elastase activity.…”

“…However, sputum color is a more reliable indicator of bacterial infection requiring antibiotic treatment and the associated increase in sputum elastase activity. 29 Therefore, patients experiencing a change in sputum color ( Figure 2) should be advised to seek medical treatment and should be prescribed antibiotic therapy as early as possible to reduce exacerbation length, elastase activity, and protect lung tissues, 28 which can ultimately affect disease progression.…”