Evaluation of ankylosing spondylitis quality of life (EASi-QoL): reliability and validity of a new patient-reported outcome measure
Haywood, Kirstie L., Garratt, Andrew M., Jordan, Kelvin P., Healey, Emma L. and Packham, Jonathan C.. (2010) Evaluation of ankylosing spondylitis quality of life (EASi-QoL): reliability and validity of a new patient-reported outcome measure. Journal of Rheumatology, Vol.37 (No.10). pp. 2100-2109. ISSN 0315-162XFull text not available from this repository.
Official URL: http://dx.doi.org/10.3899/jrheum.091359
Objective. There is currently no universally accepted measure of quality of life in ankylosinu spondylitis (AS). Our objective was to develop and evaluate a patient-reported outcome measure of quality of life in AS, EASi-QoL.
Methods. We used patient interviews, a literature review, and completion of an individualized measure of AS quality of life during clinic-based and pilot surveys to derive questionnaire content. Classical and modern psychometrics were then used to evaluate the questionnaire using data from a large UK-based postal survey of 1000 patients with AS.
Results. Data analysis from the interviews and clinic-based and postal surveys produced a 57-item self-completed questionnaire. Fifteen items were removed as a result of patient interviews and the pilot survey. In total, 612 (64.0%) patients responded to the main postal survey. After assessment of data quality, confirmatory factor analysis, and Rasch analysis, 20 items were found to contribute to 4 domains of AS-related quality of life: physical function, disease activity, emotional well-being, and social participation. Item-total correlations ranged from 0.66 to 0.84. Cronbach's alpha and test-retest reliability estimates were 0.88-0.92 and 0.88-0.93, respectively. Confirmed hypothesized correlations with the AS Quality of Life questionnaire, the Bath AS Disease Activity Index, Bath AS Functional Index, SF-36, EQ-5D, and the Hospital Anxiety and Depression Scale were evidence for the construct validity of the EASi-QoL.
Conclusion. The EASi-QoL has good evidence of data quality, internal reliability, test-retest reliability, and content and construct validity, and should be considered for use with patients in routine practice settings and in evaluative studies including clinical trials. Measurement responsiveness and minimal important change are currently being assessed. (First Release August 1 2010: J Rheumatol 2010;37:2100-9; doi:10.3899/jrheum.091359)
|Item Type:||Journal Article|
|Subjects:||R Medicine > RC Internal medicine|
|Divisions:||Faculty of Social Sciences > School of Health and Social Studies|
|Journal or Publication Title:||Journal of Rheumatology|
|Publisher:||Journal of Rheumatology Publishing Co. Ltd.|
|Official Date:||October 2010|
|Number of Pages:||10|
|Page Range:||pp. 2100-2109|
|Access rights to Published version:||Restricted or Subscription Access|
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