**1. Introduction**

Chronic obstructive pulmonary disease (COPD) is characterized by significant functional limitation and high mortality. COPD exacerbations are associated with disease progression and are one of the leading causes of hospitalization and death, emphasizing the necessity of interventions to prevent or mitigate exacerbations. Medication management, patient education, exacerbation action plans, and pulmonary rehabilitation are all important aspects of COPD treatment [1]. Pulmonary rehabilitation, which consists of exercise and self-management education, is considered critical in the treatment of COPD patients. However, these improvements are not maintained long term. At 12 months following pulmonary rehabilitation, measures of exercise capacity, symptoms, and health-related quality of life (HRQoL) have returned toward their pre-rehabilitation values [2]. It is possible that exacerbations in the post-pulmonary rehabilitation period contribute to the lack of sustained benefit at 12 months, but this has not been systematically evaluated. Understanding the effects of exacerbations on long-term results and who is at risk

for exacerbations can help with the development of more effective maintenance strategies following pulmonary rehabilitation [1, 2].
