was used for the analysis.
Functional capacity. Spirometry and whole-body plethysmography
were performed using standard equipmentc according
to the American Thoracic Society and the European Respiratory
Society recommendations.29 Reported spirometry
results were based on the best curve from 3 acceptable efforts
(after the inhalation of 200g of salbutamol); they are presented as a percentage of the predicted value.30 Dyspnea symptoms
at rest were assessed using the modified Medical Research
Council dyspnea scale.31 COPD-specific HRQOL was
evaluated by means of a validated version of the St. George’s
Respiratory Questionnaire (SGRQ).32,33 The 6-minute walk
test (6MWT) was used to assess exercise tolerance and performed
according to American Thoracic Society recommendations.34
The largest distance from 2 tests was used in the
analysis, and the normal values used were those described by
Iwama et al.35 The body mass index, airflow obstruction,
dyspnea, and exercise capacity values were integrated into a
score—the BODE index