Background
The GOLD multidimensional classification of COPD severity combines the exacerbation
risk with the symptom experience, for which 3 different questionnaires are permitted. This
study investigated differences in physical activity (PA) in the different GOLD quadrants and
patient’s distribution in relation to the questionnaire used.
Methods
136 COPD patients (58±21% FEV1 predicted, 34F/102M) completed COPD assessment
test (CAT), clinical COPD questionnaire (CCQ) and modified Medical Research Council
(mMRC) questionnaire. Exacerbation history, spirometry and 6MWD were collected. PA
was objectively measured for 2 periods of 1 week, 6 months apart, in 5 European centres;
to minimise seasonal and clinical variation the average of these two periods was used for
analysis.
Results
GOLD quadrants C+D had reduced PA compared with A+B (3824 [2976] vs. 5508 [4671]
steps.d-1, p<0.0001). The choice of questionnaire yielded different patient distributions (agreement mMRC-CAT κ = 0.57; CCQ-mMRC κ = 0.71; CCQ-CAT κ = 0.72) with different
clinical characteristics. PA was notably lower in patients with an mMRC score 2 (3430
[2537] vs. 5443 [3776] steps.d-1, p <0.001) in both the low and high risk quadrants.
Conclusions
Using different questionnaires changes the patient distribution and results in different clinical
characteristics. Therefore, standardization of the questionnaire used for classification is
critical to allow comparison of different studies using this as an entry criterion.