Impact of COPD exacerbations on patient-centered outcomes

BACKGROUND: Frequent exacerbations are associated with a faster decline in FEV(1), impaired health status, and worse survival. Their impact and temporal relationship with other outcomes such as functional status, dyspnea, and the multidimensional body mass index, obstruction, dyspnea, exercise capacity (BODE) index remain unknown. HYPOTHESIS: We reasoned that exacerbations affect the BODE index and its components, and that changes in the BODE index could be used to monitor the effect of exacerbations on the host. STUDY DESIGN: Prospective observational study in a Veterans Affairs medical center. METHODS: We studied 205 patients with COPD (mean [+/- SD] FEV(1), 43 +/- 15% predicted), and recorded the body mass index, FEV(1) percent predicted, modified Medical Research Council dyspnea scale, 6-min walk distance, and the BODE index at baseline, during the exacerbation, and at 6, 12, and 24 months following the first episode, and documented all exacerbations for 2 years after the first acute exacerbation. RESULTS: From the cohort, 130 patients (63%) experienced 352 exacerbations or (0.85 exacerbations per patient per year); 48 patients (23%), experienced one episode, 82 patients (40%) experienced 2 or more exacerbations, and 50 patients required hospitalization. At study entry, exacerbators had a worse mean baseline BODE index score (4.2 +/- 2.1 vs 3.57 +/- 2.3, respectively; p < 0.03). The BODE index score worsened by 1.38 points during the exacerbation, and remained 0.8 and 1.1 points above baseline at 1 and 2 years, respectively. There was little change in BODE index score at 2 years in nonexacerbators. CONCLUSION: COPD exacerbations negatively impact on the BODE index and its components. The BODE index is a sensitive tool used to assess the impact of exacerbations and to monitor COPD disease progression.