title: Validation of the Oxford Participation and Activities Questionnaire.
abstract: OBJECTIVE
  There is growing interest in the management of long-term conditions and in keeping people active and participating in the community. Testing the effectiveness of interventions that aim to affect activities and participation can be challenging without a well-developed, valid, and reliable instrument. This study therefore aims to develop a patient-reported outcome measure, the Oxford Participation and Activities Questionnaire (Ox-PAQ), which is theoretically grounded in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF) and fully compliant with current best practice guidelines.
  
  
  METHODS
  Questionnaire items generated from patient interviews and based on the nine chapters of the ICF were administered by postal survey to 386 people with three neurological conditions: motor neuron disease, multiple sclerosis, and Parkinson's disease. Participants also completed the Medical Outcomes Study (MOS) 36-Item Short Form Health Survey (SF-36) and EQ-5D-5L.
  
  
  RESULTS
  Thus, 334 participants completed the survey, a response rate of 86.5%. Factor analysis techniques identified three Ox-PAQ domains, consisting of 23 items, accounting for 72.8% of variance. Internal reliability for the three domains was high (Cronbach's α: 0.81-0.96), as was test-retest reliability (intraclass correlation: 0.83-0.92). Concurrent validity was demonstrated through highly significant relationships with relevant domains of the MOS SF-36 and the EQ- 5D-5L. Assessment of known-groups validity identified significant differences in Ox-PAQ scores among the three conditions included in the survey.
  
  
  CONCLUSIONS
  Results suggest that the Ox-PAQ is a valid and reliable measure of participation and activity. The measure will now be validated in a range of further conditions, and additional properties, such as responsiveness, will also be assessed in the next phase of the instrument's development.
authors.affiliation: Health Services Research Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK.
authors.forename: David
authors.initials: D
authors.lastname: Morley
authors.affiliation: Health Services Research Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Dummett
authors.affiliation: Health Services Research Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK.
authors.forename: Laura
authors.initials: L
authors.lastname: Kelly
authors.affiliation: Health Services Research Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK.
authors.forename: Jill
authors.initials: J
authors.lastname: Dawson
authors.affiliation: Health Services Research Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK.
authors.forename: Ray
authors.initials: R
authors.lastname: Fitzpatrick
authors.affiliation: Health Services Research Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK.
authors.forename: Crispin
authors.initials: C
authors.lastname: Jenkinson
keywords: FDA; ICF; PROM; activity; participation; patient-reported outcome measure; questionnaire; reliability; validity