ACR Meeting Abstracts

ACR Meeting Abstracts

Abstract Number: 3179

Scale Structure and Measurement Properties of a Disease Specific Patient-Reported Outcome for Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis

Joanna C. Robson1,2,3, Jill Dawson4, Judy A. Shea5, Helen Doll6, Susan Ashdown7, Renee Borchin8, Ebony Easley9, John T. Farrar10, Don Gebhart11, Katherine Kellom12, Georgia Lanier13, Raashid Luqmani14, Carol A McAlear15, John Mills16, Nataliya Milman17,18,19, Jacqueline Peck7, Gunnar Tomasson20, Peter F. Cronholm9 and Peter A. Merkel21, 1Faculty of Health and Applied Science, University of the West of England, Bristol, United Kingdom, 2Department of Rheumatology, University Hospitals Bristol NHS Trust, Bristol, United Kingdom, 3School of Clinical Sciences, University of Bristol, Bristol, United Kingdom, 4Nuffield Department of Population Health HSRU, University of Oxford, Oxford, United Kingdom, 5Division of General Internal Medicine, University of Pennsylvania, Philadelphia, PA, 6Department of Population Health, University of East Anglia, Norwich, United Kingdom, 7Oxford, Oxford, United Kingdom, 8University of South Florida, Tampa, FL, 9Department of Family Medicine and Community Health, The University of Pennsylvania, Philadelphia, PA, 10University of Pennsylvania, Philadelphia, PA, 11Columbus, Columbus, OH, 12PolicyLab, Children's Hospital of Philadelphia, Philadelphia, PA, United Kingdom, 13NONE, Framingham, MA, 14NDORMS , Rheumathology, Nuffield Department of Orthopaedics Rheumatology and Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Oxford, United Kingdom, 15Penn Vasculitis Center, Division of Rheumatology, University of Pennsylvania, Philadelphia, PA, 16Vasculitis UK, Sheffield, United Kingdom, 17Department of Medicine, University of Ottawa, Ottawa, ON, Canada, 18The Ottawa Hospital, Ottawa, ON, Canada, 19Department of Clinical Epidemiology, Ottawa Hospital Research Institute, Ottawa, ON, Canada, 20Dept of Public Health Sciences, University of Iceland, Reykjavik, IS, 21Division of Rheumatology, University of Pennsylvania, Philadelphia, PA

Meeting: 2016 ACR/ARHP Annual Meeting

Date of first publication: September 28, 2016

Keywords: , , ,

Session Information

Date: Wednesday, November 16, 2016

Title: Vasculitis IV: Diagnosis and Assessment of Disease Activity

Session Type: ACR Concurrent Abstract Session

Session Time: 9:00AM-10:30AM

Background/Purpose:  ANCA-associated vasculitis (AAV) is an organ- and life-threatening disease. Patients present with active disease, followed by periods of remission and flare, and have impairments in mental and physical wellbeing due to disease and treatment. An international team has developed a disease- specific patient- reported outcome measure: the AAV-PRO, supported by a steering group, including four patient partners, in collaboration with the Outcome Measures in Rheumatology (OMERACT) Vasculitis Working group. Candidate questionnaire items were produced following in-depth qualitative research in the UK, US, and Canada plus cognitive interviews, extensive piloting and independent linguistic and translatability assessment.

Methods:  Patients with AAV were recruited from Vasculitis UK, and the Vasculitis Patient-Powered Research Network, US. Patients completed the 35 candidate questionnaire items, plus information about their disease, at baseline and three months (included transition item charting change). Paper copies were used in the UK and an electronic online version in the US. UK patients also completed the Euro-Qol-5D (EQ-5D-5L). In the US, a test-retest exercise was completed 3-5 days following baseline. Exploratory factor analysis (EFA) and Rasch analysis defined the underlying scale (domain) structure. The following properties were determined for each domain: convergent validity, using Pearson correlations between domain scores and the EQ-5D-5L; known groups validity, using t-tests to compare mean scores for different disease states; test-retest reliability, analysing intraclass correlation coefficients (ICC), with respondents reporting “no change”; and longitudinal construct validity, analysing mean change scores and effect sizes in relation to transition item responses at three months.

Results:  The survey included 626 patients with AAV, mean age 59.9 years (standard deviation (SD) 13.9), 29% reported current “active disease” and 43% a flare within the last 2 years. EFA and Rasch analysis supported a 29-item profile measure comprising 6 domains: “Organ-Specific Symptoms”, “Systemic Symptoms”, “Treatment Side Effects”, “Social and Emotional Impact”, “Concerns about the Future”, and “Physical Function”. Domains individually fitted the Rasch model (no significant item-trait interaction at the 1% level) and had good internal consistency (Cronbach’s alphas 0.73 to 0.93). Mean AAV-PRO domain scores were all higher for patients reporting “active disease” versus “remission” (all p<0.001). Correlations between domain scores and the EQ-5D-5L index ranged from r0.55 to r-0.78. In respondents reporting “no change” (n=97), ICC values were high (range 0.89 to 0.96) for comparisons of each domain’s 3-5 day test re-test scores. Comparison of mean score changes and effect sizes (ES) for each domain demonstrated stable scores in those reporting “no change” and appropriate positive and negative changes in “much better” or “much worse” disease.

Conclusion:  The AAV-PRO, a new disease-specific PRO measure for use in ANCA-associated vasculitis, has good face, content, and construct validity, is reliable, feasible, and discriminates among disease states of importance.

Disclosure: J. C. Robson, None; J. Dawson, None; J. A. Shea, None; H. Doll, None; S. Ashdown, None; R. Borchin, None; E. Easley, None; J. T. Farrar, None; D. Gebhart, None; K. Kellom, None; G. Lanier, None; R. Luqmani, None; C. A. McAlear, None; J. Mills, None; N. Milman, None; J. Peck, None; G. Tomasson, None; P. F. Cronholm, None; P. A. Merkel, Bristol Myers Squibb, 2,CaridianBCT, 2,Celgene, 2,Chemocentryx, 2,Genentech/Roche, 2,GlaxoSmithKline, 2,Kypha, 2,Bristol-Myers Squibb, 5,Chemocentryx, 5,Genentech/Roche, 5,GlaxoSmithKline, 5,PrinicipioBio, 5,Auven, 5,Proteon Therapeutics, 5.

To cite this abstract in AMA style:

Robson JC, Dawson J, Shea JA, Doll H, Ashdown S, Borchin R, Easley E, Farrar JT, Gebhart D, Kellom K, Lanier G, Luqmani R, McAlear CA, Mills J, Milman N, Peck J, Tomasson G, Cronholm PF, Merkel PA. Scale Structure and Measurement Properties of a Disease Specific Patient-Reported Outcome for Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis [abstract]. Arthritis Rheumatol. 2016; 68 (suppl 10). https://acrabstracts.org/abstract/scale-structure-and-measurement-properties-of-a-disease-specific-patient-reported-outcome-for-anti-neutrophil-cytoplasmic-antibody-associated-vasculitis/. Accessed .

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