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Background Accurate measurement of disease activity is important for optimal management of patients with rheumatoid arthritis (RA). Better understanding of similarities and differences among the available clinical and biomarker-based disease activity measures may improve their use for therapeutic decision-making. Objectives Evaluate the relationship between available disease activity indices and their association with other clinical variables. Methods A cross-sectional analysis was performed for 734 RA patients enrolled in the University of Pittsburgh Rheumatoid Arthritis Comparative Effectiveness Registry (RACER), using all first visits and excluding patients (N=6) who were receiving tocilizumab. Spearman9s rank correlation and percentage agreement among 4 disease activity categories (remission, low, moderate, high) were calculated for Disease Activity Score 28 with C-reactive protein (DAS28-CRP), Clinical Disease Activity Index (CDAI), Simplified Disease Activity Index (SDAI), Routine Assessment of Patient Index 3 (RAPID3) and the Multi-biomarker Disease Activity (MBDA) score. Univariate regression analyses were performed to assess association between each disease activity score and American College of Rheumatology (ACR) Core Data Set measures, demographics, and co-morbidities. P-values were adjusted for multiple comparisons using the Benjamini-Hochberg procedure. Results For 734 patients, mean age and disease duration were 60 and 15 years, respectively. Mean RAPID3, DAS28-CRP, SDAI, CDAI, and MBDA scores were 3.6, 3.3, 15.1, 14.1, and 41.3, respectively. Each disease activity measure was significantly correlated with the others. DAS28-CRP, CDAI, and SDAI correlated strongly with each other (r=0.92–0.99) and to a lesser degree with RAPID3 (r=0.65–0.66) and MBDA score (r=0.35–0.51). Correlation between MBDA score and RAPID3 was lowest (r=0.27). Agreement among categories between DAS28-CRP and CDAI or SDAI was 45% and 56%, respectively, and between CDAI and SDAI was 88%. Agreement between DAS28-CRP and RAPID3 or MBDA score was 47% and 44%, respectively. Agreement between RAPID3 and MBDA score was 38%. All 7 ACR Core measures were significantly associated with disease activity for each index (Figure). RAPID3 was significantly associated with all measured comorbidities and opiate use; DAS28-CRP, SDAI, and CDAI with fibromyalgia and opiate use; and MBDA score with the Deyo-Charlson comorbidity index. DAS28-CRP, SDAI, and CDAI were not significantly associated with the demographic variables. RAPID3 was significantly associated with race and BMI, and MBDA score with age and BMI. Only MBDA score was significantly associated with seropositivity and not with the Short Form Health Survey (SF12) mental composite score Conclusions Disease activity indices were significantly correlated with each other and associated with ACR core measures. However, they differed in their relationships with co-morbidities or demographics. These results suggest that disease activity may not be comprehensively assessed by any single composite measure. Disclosure of Interest Y. G. Hwang: None declared, G. Wu Shareholder of: Myriad Genetics, Inc, Employee of: Crescendo Bioscience, J. Feng: None declared, J. Lyons: None declared, H. Eng: None declared, S. Wisniewski: None declared, C. Hwang Shareholder of: Myriad Genetics, Inc, Employee of: Crescendo Bioscience, E. Sasso Shareholder of: Myriad Genetics, Inc, Employee of: Crescendo Bioscience, O. Segurado Shareholder of: Myriad Genetics, Inc, Employee of: Crescendo Bioscience, L. Moreland: None declared

Background The European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) recommend that rheumatoid arthritis (RA) patients should be treated to the target of low disease activity or remission with traditional and biologic disease-modifying anti-rheumatic drugs (collectively referred to as DMARDs). However, significant numbers of RA patients in the US and Canada do not receive care consistent with these recommendations. 1,2 Objectives To determine the influence of patient and physician factors on the decision to adjust DMARD therapy for RA patients with moderate to high disease activity. Methods Data was drawn from the University of Pittsburgh Rheumatoid Arthritis Comparative Effectiveness Research (RACER) observational registry (2009-12) on visits where patients had moderate to high disease activity for at least 3 months. Therapy adjustment was defined as adding, switching, or increasing the dose of DMARD therapy. Generalized estimating equations (GEE) with clustering by patient were used to assess the relationship between patient and physician factors and whether or not therapy was adjusted. After selecting a correlation structure, variables significant in univariable GEE analyses (Wald test on coefficient has p 0.05. The model controlled for patient demographic and disease characteristics: age, race, gender, RA duration, Disease Activity Score-28 joint (DAS28-CRP), Short Form 12 (SF12) physical and mental components, and Health Assessment Questionnaire (mdHAQ). Results There were 529 visits for 348 patients with moderate to high disease activity for at least 3 months. Therapy was adjusted at 24.8% of visits. The final GEE model used an exchangeable correlation structure to account for correlation between different visits for each patient. The odds ratios (OR; [95% CI]) of adjusting therapy were decreased by older patient age (0.980; [0.961,0.999]), longer disease duration (0.980; [0.962,0.999]), years since physician medical school graduation (0.958; [0.933,0.982]), being African American (0.511; [0.276,0.946]), current use of biologic therapy (0.437; [0.263,0.728]), and lower DAS28-CRP (0.556; [0.413,0.749]). Conclusions In the RACER observational cohort, 75.2% of RA patients with moderate/high disease activity for at least 3 months did not have DMARD therapy adjusted. Patient age, years of physician experience, duration of RA, lower DAS28, being African American, and current use of biologic therapy decreased the likelihood of therapy adjustment. While the estimated impact is milder for patient age, years of physician experience and duration of RA, the data suggests more substantial impact due to DAS28-CRP, being African American, and current use of biologic therapy. Our future research will explore how other factors such as comorbidities, prior use of DMARDs and use of corticosteroids may contribute to the observed effects. References Harrold et al (2012). Arthritis Rheum, 64(3): 630-8. Lacaille et al (2005). Arthritis Care Res, 53(2): 241-8. Acknowledgements Funding for the RACER registry and research personnel is provided by Genentech. Disclosure of Interest Y. Shaw Grant/research support from: Genentech, C.-C. Chang: None Declared, H. Eng Grant/research support from: Genentech, I. Metes Grant/research support from: Genentech, L. Moreland Grant/research support from: Genentech, S. Wisniewski Grant/research support from: Genentech, M. Roberts: None Declared, M. Levesque Grant/research support from: Genentech

Background/purpose RA patients meeting the new American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) definition of remission should have better clinical outcomes than those with low disease activity. Therefore, the authors compared functional ability, health-related quality of life (HRQOL), work impairment and medication use between those meeting new ACR/EULAR remission and those in low disease activity or other defined states of remission. Method Subjects were from the University of Pittsburgh Rheumatoid Arthritis Comparative Effectiveness Research (RACER) registry (n=721). The authors analysed self-administered patient questionnaires (routine assessment of patient index-3 (RAPID3)), short form-12 (SF12), work productivity and activity impairment (WPAI)), physician exam data (disease activity score-28 joint count (DAS28) and clinical disease activity index (CDAI)) from a single RACER visit. Subjects were grouped according to whether they met ACR/EULAR remission, DAS28 and CDAI remission, low, moderate and high disease activity. Demographics, questionnaire data and medication use were compared between those who did not fulfil the new remission criteria but did fulfil other remission and low disease activity states using Mann–Whitney U and Pearson χ2 tests. Result ACR/EULAR remission was achieved by 17.6% of the cohort. Age, sex, race and disease duration were similar between disease activity groups. The mean SF-12 physical and mental component scores (PCS/MCS) for subjects in ACR/EULAR remission were similar to healthy, comparably aged subjects. Subjects in CDAI remission (n=109) also met ACR/EULAR remission and had comparable SF-12, WPAI and RAPID3 scores (data not shown). In contrast, not all subjects in DAS28 remission (n=274) also met the ACR/EULAR definition of remission (n=127). Subjects in DAS28 remission but not ACR/EULAR remission (n=147) and subjects in DAS28 and CDAI low disease activity had worse SF12, WPAI and RAPID3 scores (table 1). The use of DMARDs and/or biologics was similar between the remission and low disease activity groups. However, the ACR/EULAR and CDAI remission groups used significantly less opiates and corticosteroids than subjects in DAS remission and all other disease activity groups (p Conclusion RA subjects in ACR/EULAR remission had a quality of life similar to healthy comparably aged subjects suggesting that the new ACR/EULAR remission criteria represent a true state of remission. The DAS28 definition of remission is not comparable since RA subjects in ACR/EULAR remission had better RAPID3, SF12 and WPAI scores. ACR/EULAR remission was associated with improved functional ability, HRQOL and work productivity compared to DAS28 and CDAI low disease activity. Medication data suggests that for subjects not in remission, achieving remission will require more optimal and/or greater use of combinations of immunosuppressive therapies. Our future goal is to determine the cost-effectiveness and the risk:benefit of more aggressive treatment approaches for patients not yet in remission and to study remission longitudinally.