Introduction

1. T H E N O R T H S T A F F O R D S H I R E P R I M A R Y C A R E R E S E A R C H C O N S O R T I U M Keele Assessment of Participation (KAP): A new instrument for measuring participation restriction in population surveys Ross Wilkie, George Peat, Elaine Thomas, Peter Croft Primary Care Musculoskeletal Research Centre, Keele University, Staffordshire, UK. Contact details: r.wilkie@cphc.keele.ac.uk Further details of this work are published: Wilkie et al., Qual Life Res 2005;14(8):1889-99. • Introduction • Participation restriction refers to the social consequences of ill-health (World Health Organization, 2001). • From a systematic search and review of existing health measurement instruments we found that (i) there were none which could provide a score exclusive to participation restriction and (ii) the concept of participation restriction, as presented by the World Health Organization, was ambiguous (Wilkie et al., Arthritis Rheum 2004;51:755-62). • Aims • To propose a conceptual model, measurement model and self-complete instrument suitable for epidemiological studies measuring participation restriction. • To examine the psychometric properties of the proposed instrument. • Conceptual model • Participation restriction is a performance-based context-dependent phenomenon. • Participation restriction is a person-perceived phenomenon requiring the judgement of the individual. • Participation restriction is not a fixed state but may be experienced intermittently within a given time. • There are an infinite number of life situations that can be organised under the WHO domains for the measurement of participation restriction: domains are mutually exclusive.The domains of mobility, self-care, domestic life, interpersonal interaction, major life, and community, social and civic life were determined a priori to reflect participation restriction. • Participation restriction across multiple domains is summative with restriction in more domains indicating greater participation restriction. Keele Assessment of Participation (KAP) 1.During the past 4 weeks, I have moved around in my home, as and when I have wanted.* 2.  During the past 4 weeks, I have moved around outside my home, as and when I have wanted.*  3.  During the past 4 weeks, my self-care needs (examples are washing, toileting, dressing, feeding, maintaining health) have been met, as and when I have wanted.* 4.  During the past 4 weeks, my home has been looked after, as and when I have wanted.* 5.  During the past 4 weeks, my things (belongings) have been looked after, as and when I have wanted.* 6.  Do you have any relatives, or other people, who depend on you? (Yes/No) ‡ If yes, during the past 4 weeks, were these people looked after, as and when you wanted?*  7.  During the past 4 weeks, I have met and spoken to other people as and when I have wanted. * 8.  During the past 4 weeks, I, or someone else on my behalf, have managed my money, as I have wanted.* 9.  Do you choose to take part in paid or voluntary work? (Yes/No) ‡ If yes, during the past 4 weeks, have you taken part in paid or voluntary work, as and when you have wanted? * 10. Do you choose to take part in education or training courses? (Yes/No) ‡ If yes, during the past 4 weeks, have you taken part in education or training, as and when you have wanted?* 11. Do you choose to take part in social activities? (Yes/No) ‡ If yes, during the past 4 weeks, have you taken part in social activities, as and when you have wanted?* *Response options: All the time/ Most of the time/ Some of the time/ A little of the time/ None of the time. ‡ Filter questions were added following the pre-testing stage • Example item: Mobility within the home • Estimates of prevalence can be produced for: • Any restriction – restriction in at least one aspect of life • ii. Participation restriction in each aspect of life Measures individuals’ perception Measures performance not just capacity During the last 4 weeks, I have moved around my home, as and when I have wanted? All Most of Some of A little None of the time the time the time of the time the time Participation restriction Participation • Methods: Examination of the psychometric properties of the KAP • Cognitive interviews: purposive sample of adults with rheumatoid arthritis (n=7) and “healthy” adults (n=4). • Qualitative interviews: purposive sample of adults with rheumatoid arthritis (n=4). • Pilot study: the sampling frame consisted of 1500 randomly selected adults aged 50 years and over who were registered with one general practice in North Staffordshire. • Repeatability: 4 weeks between the first and second mailings. • Convergent validity: KAP items were compared with items from the Re-integration to Normal Living (RNL) (Wood-Dauphinee,1988) and the Impact on Participation and Autonomy (IPA) (Cardol, 2001). • Divergent validity: KAP items were compared with items measuring the frequency of participation restriction. • Results of psychometric testing • Face validity • All items and instructions were easily understood, completed in line with the conceptual model and were judged broadly relevant and acceptable by potential responders. • Content validity • No additional domains were suggested by participants. The KAP appeared to comprehensively measure participation restriction. • Responder burden • No excessive physical or emotional strain apparent during completion of the KAP. Mean completion time: 3 mins. • Completion rates for KAP items • Mean: 98.2% (Range: 97.0% - 99.5%). • Distribution • Range of prevalence of participation restriction across 11 domains: • 4% - 18%. • Prevalence of any restriction: 53%. • Repeatability • Mean percentage agreement for KAP items was 90.4%. • Systematic difference in the prevalence of any restriction between the two mailings (%difference: -9.4; 95%CI: -1.4%, -17.3%). • Convergent validity • High levels of agreement with 2 comparative instruments • (i.e. mean agreement between items of the KAP and the RNL: 79.3%; mean agreement between items of the KAP and the IPA: 87.7%). • Divergent validity • Person-perceived participation restriction was distinct from the • actual frequency of participation restriction in life situations. Cognitive interviews (n=11): Face validity, Content validity Respondent burden Pre-testing interview stage Qualitative interviews (n=4): Face validity Content validity Pilot questionnaire stage (n=1117): Completion rates Distribution of KAP Discriminant validity (Conceptual) Repeatability (n=196) Test retest Validity (n=106) Convergent validity • Discussion • The KAP was designed to be a short and simple questionnaire for application in population studies and can estimate prevalence for any participation restriction and restriction in each aspect of life. • Further testing would help understand individuals’ “judgement” on their participation and reasons for response shift over time. • The KAP can be used to provide estimates of person-perceived participation restriction in population surveys. This work is funded by a Programme Grant awarded by the Medical Research Council, UK (grant code:G9900220) and by North Staffordshire Primary Care R & D Consortium for NHS service support costs. We would also like to acknowledge the work of Helen Hooper (qualitative interviews), and the administrative and health informatics staff at Primary Care Musculoskeletal Research Centre.