The following is a summary of “Clusters of individuals recovering from an exacerbation of chronic obstructive pulmonary disease and response to in-hospital pulmonary rehabilitation,” published in the May–June 2023 issue of Pulmonology by Vitacca, et al.
Pulmonary rehabilitation (PR) is limited for individuals recovering from a COPD exacerbation (ECOPD), highlighting the need for admission priority criteria. For a study, researchers sought to test the hypothesis that the individuals can be clustered based on baseline characteristics to identify subpopulations with varying responses to PR.
The multicenter retrospective analysis included individuals who underwent in-hospital PR. Baseline characteristics and outcome measures (six-minute walking test – 6MWT, Medical Research Council scale for dyspnea – MRC, COPD assessment test – CAT) were used for clustering analysis.
Data analysis from 1,159 individuals revealed that after the PR program, 85.0%, 86.3%, and 65.6% of individuals reached the minimal clinically important difference (MCID) for CAT, MRC, and 6MWT, respectively. Three clusters were identified: C1 (severe, 10.9% of cases), C2 (intermediate, 74.4% of cases), and C3 (mild, 14.7% of cases). Cluster C1, representing severe baseline conditions, significantly improved outcome measures after PR. Cluster C3, representing the mildest baseline conditions, showed the smallest improvements. The proportion of participants achieving MCID in all three outcome measures differed significantly among clusters, with C1 having the highest proportion of success (69.0%), followed by C2 (48.3%) and C3 (37.4%). Participants in C2 and C1 had 1.7- and 4.6-fold higher probabilities, respectively, of reaching MCID in all three outcomes compared to those in C3 (OR = 1.72, 95% CI = 1.2–2.49, P = 0.0035, and OR = 4.57, 95% CI = 2.68–7.91, P < 0.0001).
Clustering analysis can identify subpopulations of individuals recovering from ECOPD with different responses to PR. The findings may aid in establishing priority criteria based on the likelihood of PR success.