title: The PROactive instruments to measure physical activity in patients with chronic obstructive pulmonary disease.
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.
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain Universitat Pompeu Fabra (UPF), Barcelona, Spain FCS Blanquerna, Research Group in Physiotherapy (GReFis), Universitat Ramon Llull, Barcelona, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Gimeno-Santos
authors.affiliation: National Institute for Health Research Respiratory Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust and Imperial College, London, UK.
authors.forename: Yogini
authors.initials: Y
authors.lastname: Raste
authors.affiliation: Department of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences and Respiratory Division, University Hospital Leuven, Leuven, Belgium.
authors.forename: Heleen
authors.initials: H
authors.lastname: Demeyer
authors.affiliation: Department of Critical Care Medicine and Pulmonary Services, Thorax Foundation, Athens, Greece.
authors.forename: Zafeiris
authors.initials: Z
authors.lastname: Louvaris
authors.affiliation: Department of General Practice, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Corina
authors.initials: C
authors.lastname: de Jong
authors.affiliation: ELEGI Colt Laboratory, Centre for Inflammation Research, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK.
authors.forename: Roberto A
authors.initials: RA
authors.lastname: Rabinovich
authors.affiliation: National Institute for Health Research Respiratory Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust and Imperial College, London, UK.
authors.forename: Nicholas S
authors.identifier: http://orcid.org/0000-0003-3235-0454
authors.initials: NS
authors.lastname: Hopkinson
authors.affiliation: National Institute for Health Research Respiratory Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust and Imperial College, London, UK.
authors.forename: Michael I
authors.initials: MI
authors.lastname: Polkey
authors.affiliation: Department of Critical Care Medicine and Pulmonary Services, Thorax Foundation, Athens, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Vogiatzis
authors.affiliation: Value Evidence and Outcomes, GlaxoSmithKline R&D, Uxbridge, UK.
authors.forename: Maggie
authors.initials: M
authors.lastname: Tabberer
authors.affiliation: Health Services and Nursing Research, Department of Public Health and Primary Care, University of Leuven, Leuven, Belgium.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Dobbels
authors.affiliation: Almirall S.A., Barcelona, Spain.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Ivanoff
authors.affiliation: Lung Foundation Netherlands, Amersfoort, The Netherlands.
authors.forename: Willem I
authors.initials: WI
authors.lastname: de Boer
authors.affiliation: Department of General Practice, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Thys
authors.initials: T
authors.lastname: van der Molen
authors.affiliation: PRO Expert, Novartis Pharma, Basel, Switzerland.
authors.forename: Karoly
authors.initials: K
authors.lastname: Kulich
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain Universitat Pompeu Fabra (UPF), Barcelona, Spain.
authors.forename: Ignasi
authors.initials: I
authors.lastname: Serra
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain Universitat Pompeu Fabra (UPF), Barcelona, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Basagaña
authors.affiliation: Department of Rehabilitation Sciences, Faculty of Kinesiology and Rehabilitation Sciences and Respiratory Division, University Hospital Leuven, Leuven, Belgium.
authors.forename: Thierry
authors.initials: T
authors.lastname: Troosters
authors.affiliation: Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland.
authors.forename: Milo A
authors.initials: MA
authors.lastname: Puhan
authors.affiliation: Health Economics and Outcomes Research, AstraZeneca R&D, Mölndal, Sweden.
authors.forename: Niklas
authors.initials: N
authors.lastname: Karlsson
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain Universitat Pompeu Fabra (UPF), Barcelona, Spain jgarcia@creal.cat.
authors.forename: Judith
authors.initials: J
authors.lastname: Garcia-Aymerich
mesh_terms: D000368:Aged; D000465:Algorithms; D018592:Cross-Over Studies; D005060:Europe; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D011594:Psychometrics / Q000379:methods; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology* / Q000628:therapy*; D011788:Quality of Life; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires