Casanova C, Cote C, Marin JM, Pinto-Plata V, de Torres JP, Aguirre-JaÃme A, Vassaux C, Celli BR.
In this study 576 stable COPD outpatients in Spain and the United States were enrolled and observed them for at least 3 years. FEV1, body mass index, PaO2, Charlson comorbidity score, 6-min walk distance (6MWD), and oxygen saturation by pulse oximetry (SpO2) during the 6MWT. Regression analysis helped determine the association between these variables and all-cause and respiratory mortality.
The results showed that the 6MWD was a good predictor of all-cause and respiratory mortality primarily in patients with FEV1 < 50% of predicted. Patients with desaturation during the 6MWT had a higher mortality rate than patients without desaturation. Oxygen desaturation (drop of >4% or less than 90%) predicted mortality but with less power than PaO2 at rest.
Chest 2008; 134: 746 â€“ 752