Figure 2.

Stability of the phenotypes of frequent and infrequent exacerbators, nonexacerbators, and severe exacerbators.

Notes: ^#Three patients who had subsequent severe exacerbations in 78 completed patients, and two of 17, zero of eleven, and one of 50 patients were frequent, infrequent, and nonexacerbators, respectively (dotted lines). Two frequent exacerbators required hospitalization due to COPD exacerbations, and one died due to respiratory failure. In analysis of subphenotypes with severe exacerbators, two of five patients had subsequent severe exacerbations (dotted line). The bars at the previous (left) and future (right) risk show the proportions of patients who suffered severe, frequent, and infrequent exacerbations, and nonexacerbators retrospectively and prospectively, respectively, based on the number of previous moderate and severe exacerbations for 1 year.