The PROactive instruments to measure physical activity in patients with chronic obstructive pulmonary disease.
Author(s)
Type
Journal Article
Abstract
No current patient-centred instrument captures all dimensions of physical activity in chronic obstructive pulmonary disease (COPD). Our objective was item reduction and initial validation of two instruments to measure physical activity in COPD.Physical activity was assessed in a 6-week, randomised, two-way cross-over, multicentre study using PROactive draft questionnaires (daily and clinical visit versions) and two activity monitors. Item reduction followed an iterative process including classical and Rasch model analyses, and input from patients and clinical experts.236 COPD patients from five European centres were included. Results indicated the concept of physical activity in COPD had two domains, labelled "amount" and "difficulty". After item reduction, the daily PROactive instrument comprised nine items and the clinical visit contained 14. Both demonstrated good model fit (person separation index >0.7). Confirmatory factor analysis supported the bidimensional structure. Both instruments had good internal consistency (Cronbach's α>0.8), test-retest reliability (intraclass correlation coefficient ≥0.9) and exhibited moderate-to-high correlations (r>0.6) with related constructs and very low correlations (r<0.3) with unrelated constructs, providing evidence for construct validity.Daily and clinical visit "PROactive physical activity in COPD" instruments are hybrid tools combining a short patient-reported outcome questionnaire and two activity monitor variables which provide simple, valid and reliable measures of physical activity in COPD patients.
Date Issued
2015-06-11
Date Acceptance
2015-03-22
Citation
European Respiratory Journal, 2015, 46 (4), pp.988-1000
ISSN
1399-3003
Publisher
European Respiratory Society: ERJ
Start Page
988
End Page
1000
Journal / Book Title
European Respiratory Journal
Volume
46
Issue
4
Copyright Statement
© ERS 2015. ERJ Open articles are open access and distributed under the terms of the Creative Commons
Attribution Non-Commercial Licence 4.0.
Attribution Non-Commercial Licence 4.0.
License URL
Identifier
PII: 09031936.00183014
Publication Status
Published