SAT0473 Defining cut-off values for disease activity states and improvement scores for patient-reported outcomes: the example of the rheumatoid arthritis impact of disease (RAID). (23rd January 2014)

• Record Type: Journal Article
• Authors: Dougados, M.; Brault, Y.; Logeart, I.; van der Heijde, D.; Gossec, L.; Kvien, T.
• Is Part Of: Annals of the rheumatic diseases. Volume 71(2012)Supplement 3
• Page Start: 632
• Page End: 632
• Publication Date: 2014-01-23
• Subjects: Rheumatism -- Periodicals; 616.723005
• DOI: 10.1136/annrheumdis-2012-eular.3419
• Languages: English
• ISSNs: 0003-4967

Abstract

Abstract : Background: The Rheumatoid Arthritis Impact of Disease (RAID) is a patient-reported outcome measure evaluating the impact of rheumatoid arthritis (RA) on patient quality of life. It comprises 7 domains that are evaluated as continuous variables from 0 (best) to 10 (worst).[1, 2] Objectives: To define/identify cut-off values for disease activity states and improvement scores in order to present results at the individual level ( e.g. patient in acceptable state, improved patient). Methods: Patients with definite active RA requiring anti-TNF therapy were seen at screening, baseline and after 4 and 12 weeks of etanercept therapy. Answers to "Gold standard" questions on improvement (MCII: Minimum Clinically Important Improvement) and an acceptable status (PASS: Patient Acceptable Symptom State) were collected as well as the RAID score and DAS28-ESR. Cut-offs were defined by different techniques ( e.g. empirical, measurement error and gold standard anchors). The external validity of these cut-offs was evaluated using the positive likelihood ratio (LR) based on the patient's perspective ( e.g. patient's global) and on low disease activity status ( e.g. DAS28-ESR). Results: Ninety-seven (97) of the 108 recruited patients (age: 54±13 years old, female gender: 75%, rheumatoid factor positive: 81%, disease duration: 8±7 years, CRP: 18±30 mg/l, DAS28-ESR: 5.4±0.8) completed the 12 weeks of the study. The different techniques suggested thresholds ranging from 0.2 to 3 (absolute change) and from 6 to 50% (relative change) for defining MCII and thresholds from less than 1 to less than 5.6 for defining PASS. The evaluation of external validity (LR+) showed the highest LR+ was obtained with thresholds of 3 for absolute change; 50% for relative change and less than 2 for an acceptable status. Conclusions: This study showed that thresholds defined for continuous variables are closely depend on the methodological technique, justifying a systematic evaluation of their validity. Our results suggested that a change of at least 3 points (absolute) or 50% (relative) in the RAID score should be used to define a MCII and that a maximal value of 2 defines an acceptable status. References: Gossec L, Dougados M, Rincheval N, et al. Elaboration of the preliminary Rheumatoid Arthritis Impact of Disease (RAID) score: a EULAR initiative. Ann Rheum Dis 2009;68:1680-5. Gossec L, Paternotte S, Aanerud GJ, et al. Finalisation and validation of the rheumatoid arthritis impact of disease score, a patient-derived composite measure of impact of rheumatoid arthritis: a EULAR initiative. Ann Rheum Dis 2011;70:935-42. Disclosure of Interest: None Declared