Prediction of risk of COPD exacerbations by the BODE index.

ABSTRACT

OBJECTIVES: This study assesses the power of the BODE index, a multidimensional grading system that predicts mortality, to predict subsequent exacerbations in patients with COPD. DESIGN: Prospective cohort study. PATIENTS AND INTERVENTIONS: A total of 275 COPD patients were followed every 6 months up to 8 years (median of 5.1 years). Baseline clinical variables were recorded and the BODE index was calculated. We investigated the prognostic value of BODE quartiles (scores 0-2, 3-4, 5-6 and 7-10) for both the number and severity of exacerbations requiring ambulatory treatment, emergency room visit, or hospitalization. RESULTS: The annual rate of COPD exacerbations was 1.95 (95% CI, 0.90-2.1). The mean time to a first exacerbation was inversely proportional to the worsening of the BODE quartiles (7.9 yrs, 5.7 yrs, 3.4 yrs and 1.3 yrs for BODE scores of 0-2, 3-4, 5-6 and 7-10, respectively). Similarly, the mean time to a first COPD emergency room visit was 6.7 yrs, 3.6 yrs, 2.0 yrs and 0.8 yrs for BODE quartiles (all p<0.05). Using ROC curves, the BODE index was a better predictor of exacerbation than the FEV(1) alone (p<0.01). CONCLUSIONS: The BODE index is a better predictor of the number and severity of exacerbations in COPD than FEV(1) alone.