Prognostic assessment in COPD: health related quality of life and the BODE index.

RATIONALE: COPD is a debilitating disease with increasing mortality worldwide. The BODE index evaluates disease severity and the St George's Respiratory Questionnaire (SGRQ) measures health status. OBJECTIVE: To identify the relationship between BODE index and the SGRQ and to test the predictive value of both tools against survival. METHODS: Open cohort study of 1398 COPD patients (85% male) followed for up to 10 years. MEASUREMENTS AND MAIN RESULTS: At the time of the inclusion, clinical data, forced spirometry and 6 min walking distance were determined and BODE index and SGRQ were calculated. Vital status and cause of death were documented at the end of follow-up. RESULTS: The cohort's mean of FEV1% predicted was 46 ± 18%, BODE index was 3.6 ± 2.5, and SGRQ% total score was 49 ± 20. The SGRQ scores increased progressively as severity of COPD increased by BODE quartiles. The correlation between SGRQ and BODE index was good (r = 0.58, p < 0.0001). Both tests correlated with COPD survival (BODE = -0.4 vs. SGRQ = -0.20, p < 0.0001). The area under the curve (AUC) for the BODE index was 0.77 vs. 0.66 for the SGRQ % total score (p < 0.001). CONCLUSIONS: Health status as measured by SGRQ worsens with disease severity evaluated by the BODE index. Both tools predict mortality and provide complimentary information in the evaluation of patients with COPD.

The 6-min walk distance, peak oxygen uptake, and mortality in COPD.

In patients with COPD, the maximal oxygen uptake (Vo2) measured at peak exercise and the 6-min walk distance (6MWD) have been associated with survival; however, no study has compared the strength of the association in the same patients. In this study, we compared the association between the 6MWD and peak Vo2 and mortality in 365 patients with COPD. Patients' cardiopulmonary cycle ergometry test results and 6MWD were determined at entry, and patients were followed up for a mean period of 67 months. There were 171 deaths. Compared with survivors, nonsurvivors were older (mean [+/- SD] age, 67.9 +/- 8 vs 65.9 +/- 8 years, respectively; p = 0.008), had worse mean FEV1 (36.5 +/- 12 vs 42.6 +/- 14 L, respectively; p = 0.02), had lower mean peak Vo2 (9.8 +/- 3 vs 11.8 +/- 3.6 mL/Kg/min, respectively; p < 0.0001), lower mean 6MWD (312 +/- 104 vs 377 +/- 95 m, respectively; p < 0.0001), and lower mean exercise minute ventilation (37.4 +/- 12 vs 42.3 +/- 13 L/min, respectively; p = 0.004). Univariate analysis showed that peak Vo2 and 6MWD as well as comorbidity, FEV1, and body mass index were associated with death. Logistic regression analysis with mortality as the dependent variable revealed that 6MWD (hazard ratio [HR], 0.996; 95% confidence interval [CI], 0.993 to 0.999; p < 0.01) had a stronger association than the peak Vo2 (HR, 0.971; 95% CI, 0.959 to 1.000; p = 0.050) with mortality. This study shows the 6MWD is as good predictor of mortality as the peak Vo2 in patients with COPD.

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.