The 12-month history of acute exacerbations used to guide most COPD treatment relies on an unstable frequent exacerbator phenotype, according to the results of a recent study published in the European Respiratory Journal.
The underlying average event rate for acute exacerbations from 2 cohorts of patients with COPD was determined and analyzed using probabilistic techniques to evaluate the stability of the frequent exacerbator phenotype. Sources of variability in the phenotype were then evaluated and characterized.
Both study cohorts demonstrated an individual-specific underlying acute exacerbation rate which is stable over time. However, variation exists within the observed rates within individuals. Patients with an underlying rate between 0.8 to 3.1 events per year had frequent exacerbator classification change >30% of the time during the course of 2 years. Furthermore, this classification change increased to >45% of the time for patients with an underlying rate between 1.2 to 2.2 events per year.
“While the underlying COPD [acute exacerbation] rate is a stable trait, the frequent exacerbator phenotype based on observed COPD [acute exacerbation] patterns is unstable, so much so that its suitability for informing treatment decisions should be questioned,” the study authors wrote. “Whether evaluating COPD [acute exacerbation] history over longer durations or the use of multivariate prediction models can result in more stable phenotyping needs to be evaluated.”
Sadatsafavi M, McCormack J, Petkau J, Lynd LD, Lee TY, Sin DD. Should the number of acute exacerbations in the previous year be used to guide treatments in COPD? Eur Respir J. Published online August 27, 2020. doi:10.1183/13993003.02122-2020