Rheumatoid Arthritis: Gilworth G

Gilworth G, Emery P, Barkham N, Smyth MG, Helliwell P, Tennant A. · Department of Rehabilitation Medicine, Section of Musculoskeletal Disease, Leeds Institute of Molecular Medicine, University of Leeds, Leeds, UK. · BMC Musculoskelet Disord. · Pubmed #19531252 links to  free full text

Abstract: BACKGROUND: The Work Instability Scale for Rheumatoid Arthritis (RA-WIS) is established and is used by physicians to identify patients at risk of job loss for rapid intervention. The study objective was to explore the concept of Work Instability (a mismatch between an individual's abilities and job demands) in Ankylosing Spondylitis (AS) and develop a Work Instability Scale specific to this population. METHODS: New items generated from qualitative interviews were combined with items from the RA-WIS to form a draft AS-WIS. Rasch analysis was used to examine the scaling properties of the AS-WIS using data generated through a postal survey. The scale was validated against a gold standard of expert assessment, a test-retest survey examined reliability. RESULTS: Fifty-seven participants who were in work returned the postal survey. Of the original 55 items 38 were shown to fit the Rasch model (chi(2) 37.5; df 38; p 0.494) and free of bias for gender and disease duration. Following analysis for discrimination against the gold standard assessments 20 items remained with good fit to the model (chi(2) 24.8; df 20; p 0.21). Test-retest reliability was 0.94. CONCLUSION: The AS-WIS is a self-administered scale which meets the stringent requirements of modern measurement. Used as a screening tool it can identify those experiencing a mismatch at work who are at risk of job retention problems and work disability. Work instability is emerging as an important indication for the use of biologics, thus the AS-WIS has the potential to become an important outcome measure.

Helliwell P, Reay N, Gilworth G, Redmond A, Slade A, Tennant A, Woodburn J. · Rheumatology and Rehabilitation Research Unit, University of Leeds, Leeds, United Kingdom. · Arthritis Rheum. · Pubmed #15934122 links to  free full text

Abstract: OBJECTIVE: To develop a new foot impact scale to assess foot status in rheumatoid arthritis (RA) using established qualitative methodology and the latest item response techniques (Rasch analysis). METHODS: Foot problems in RA were explored by conducting qualitative interviews that were then used to generate items for a new foot impact scale. Further validation was undertaken following postal surveys and Rasch analysis. RESULTS: Analysis of the first postal survey (n = 192 responses) produced a 63-item binary response, 4-subscale instrument. The 4 subscales covered the domains impairment, activities, participation, and footwear. Following test-retest postal surveys and additional analysis, the instrument was reduced to a 2 subscale, 51-item questionnaire covering the domains of impairments/shoes and activities/participation. Initial results of these subscales indicate good psychometric properties, external validity, and test-retest reliability. CONCLUSION: A foot impact scale to assess the impact of RA and to measure the effect of interventions has been developed. The 2 scales comprising the instrument demonstrate good psychometric properties.

Gilworth G, Chamberlain MA, Harvey A, Woodhouse A, Smith J, Smyth MG, Tennant A. · University of Leeds, United Kingdom. · Arthritis Rheum. · Pubmed #12794790 links to  free full text

Abstract: OBJECTIVES: To explore the concept of work instability (WI), a state in which the consequences of a mismatch between an individual's functional abilities and the demands of his or her job could threaten continuing employment if not resolved, in people with rheumatoid arthritis (RA). To develop the Work Instability Scale (WIS). METHODS: WI in people with RA was explored through qualitative interviews, which were then used to generate items for the WIS. RESULTS: Through Rasch analysis and validation against a gold standard of expert vocational assessment, a short 23-item, self administered, RA WIS was developed. CONCLUSION: The WIS can be scored in 3 bands indicating low, medium, and high risk of work disability.