The BODE index, a simple multidimensional grading system, is better than the FEV1 at predicting the risk of death from any cause and from respiratory causes among patients with COPD.

Comorbidities are frequent in COPD and 12 of them negatively influence survival. A simple disease-specific comorbidities index (COTE) helps assess mortality risk in patients with COPD.

The 6-min walk distance (6MWD) predicted values have been derived from small cohorts mostly from single countries. The aim of the present study was to investigate differences between countries and identify new reference values to improve 6MWD interpretation.We studied 444 subjects (238 males) from seven countries (10 centres) ranging 40-80 yrs of age. We measured 6MWD, height, weight, spirometry, heart rate (HR), maximum HR (HRmax) during the 6-min walk test/the predicted maximum HR (HRmax % pred), Borg dyspnoea score and oxygen saturation.The mean¡SD 6MWD was 571¡90 m (range 380-782 m). Males walked 30 m more than females (p,0.001). A multiple regression model for the 6MWD included age, sex, height, weight and HRmax % pred (adjusted r 2 50.38; p,0.001), but there was variability across centres (adjusted r 2 50.09-0.73) and its routine use is not recommended. Age had a great impact in 6MWD independent of the centres, declining significantly in the older population (p,0.001). Age-specific reference standards of 6MWD were constructed for male and female adults. In healthy subjects, there were geographic variations in 6MWD and caution must be taken when using existing predictive equations. The present study provides new 6MWD standard curves that could be useful in the care of adult patients with chronic diseases.

The 6-min walk distance: change over time and value as a predictor of survival in severe COPD. V.M. Pinto-Plata, C. Cote, H. Cabral, J. Taylor, B.R. Celli. #ERS Journals Ltd 2004. ABSTRACT: The 6-min walk distance (6MWD) is used to evaluate the functional capacity of patients with chronic obstructive pulmonary disease (COPD). The change in 6MWD over time and its correlation with changes in spirometry and survival are unclear.Patients (n=198) with severe COPD and 41 age-matched controls were followed for 2 yrs, and anthropometrics, spirometry, 6MWD and comorbidities were measured.The 6MWD decreased in the COPD group from 238¡107 m to 218¡112 m (-26¡37 m?yr -1 ), and increased in the control group from 532¡82 m to 549¡86 m (12¡25 m?yr -1 ). In both groups, there was a poor correlation with changes in forced expiratory volume in one second (FEV1). Nonsurvivors in the COPD group (42%) had a more pronounced change in the 6MWD (-40 versus -22 m?yr -1 ) but a similar change in FEV1 (118 versus 102 mL?yr -1 ). The 6MWD independently predicted survival, after accounting for age, body mass index, FEV1 and comorbidities.In severe chronic obstructive pulmonary disease, the 6-min walk distance predicts mortality better than other traditional markers of disease severity. Its measurement is useful in the comprehensive evaluation of patients with severe disease.

Static lung hyperinflation has important clinical consequences in patients with chronic obstructive pulmonary disease. We analyzed the power of lung hyperinflation as measured by the inspiratory capacity-to-total lung capacity ratio (IC/TLC) to predict mortality in a cohort of 689 patients with chronic obstructive pulmonary disease (95% males; FEV 1 , 1.17 L) with a mean follow-up of 34 months. We also compared the predictive value of IC/TLC with that of the BODE (body mass index, airflow obstruction, dyspnea, exercise performance) Index. Subjects who died (183; 27%) were older; had lower body mass index, FEV 1 , and IC/TLC ratio; walked less in the 6-minute walking distance; and had more dyspnea, a higher BODE Index, and comorbidity (p Ͻ 0.001). On the basis of logistic regression analysis, IC/TLC was found to be a good and independent predictor of all-cause and respiratory mortality. On the basis of receiver operating characteristic Type II curves, IC/TLC compared favorably with FEV 1 and predicted mortality independently of the BODE Index. We conclude that IC/TLC is an independent risk factor for mortality in subjects with chronic obstructive pulmonary disease. We propose that this ratio be considered in the assessment of patients with chronic obstructive pulmonary disease.