COPD is described as a progressive and persistent airflow limitation, with the presence of pulmonary and extrapulmonary manifestations such as dyspnea, reduced exercise capacity and muscle weakness, which impairs functional performance and physical activity as the disease worsens. The functional performance can be assessed by the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) questionnaire, as it is an instrument that encompasses biopsychosocial principles according to the International Classification of Functioning, Disability and Health, however there is no knowledge whether this instrument can track physical inactivity in this population.

To verify the correlation between WHODAS questionnaire score and physical activity levels in people with COPD.

This is a cross-sectional study, which assessed 35 patients with COPD, aged over 50 years (21 males, 69±8 years, FEV1/FVC 56 ±13%, FEV1 post-Bronchodilator 50 ± 13%). This study was approved by the Research Ethics Committee of the Federal University of São Carlos (UFSCar), under number 85901318.0.0000.55.04. To evaluate functionality, the WHODAS 2.0 questionnaire, with 36 items was applied in the interview format. The level of physical activity was assessed by the actigraph activPAL3TM (Pal Technologies Ltd., Glasgow, United Kingdom), for 7 consecutive days, by time spent sitting, standing and walking; number of steps and time spent at certain exercise intensities (sedentary, if MET <1.5 and low intensity exercise, if MET >1.5, but < 3). Participants who could not perform the proposed tests and/or had difficulty understanding the questionnaire were excluded. For data analysis and correlation, the statistical software SPSS version 21 (2012) was used, with significance established at a p value <0.05.

Significant correlation were found only between the mobility domain of WHODAS 2.0 and number of steps (r= -0.490; p=0.003), sitting time (r=0.472; p=0.004), standing time (r= -0.366; p= 0.031), walking time (r= -0.510; p= 0.002), time during MET < 1.5 (r= 0.426; p= 0.011) and time during MET >1.5, but < 3 (r= -0.428; p=0.010).

The WHODAS 2.0 mobility domain showed association with the variables that reflect the level of physical activity and sedentary time in COPD patients, thus the instrument may be effective to track physical inactivity in this population.

This study shows that the WHODAS 2.0 questionnaire is an effective tool for tracking the level of physical activity in COPD patients and can be used as a clinical outcome before and after physical therapy intervention.