Increase in axial spondyloarthritis diagnoses after the introduction of the ASAS criteria: a systematic review.

To explore the proportion of axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA) diagnoses within all newly referred patients visiting rheumatology outpatient clinics. And more specifically, to analyze whether there is an effect of the introduction of the ASAS and CASPAR classification criteria for axSpA and PsA. We systematically searched Embase, Medline Ovid, Cochrane Central and Web of Science from database inception to November 2022. Articles that investigated new onsets of axSpA and PsA in adults from rheumatology clinics were included. In total, 170 out of 7139 studies were found eligible for full-text review, after which 33 unique studies were included. Seventeen studies reported new onsets of axSpA, and 20 studies of PsA. The pooled proportion of axSpA within all newly referred patients was 19% (95% CI 15-23%) and 18% (95% CI 14-22%) for PsA. The proportion of axSpA before 2009 was 3% (95% CI 0-6%) and increased up to 21% (95% CI 14-28%) after 2009. For PsA, limited data were available in order to analyze the proportions of PsA before 2006. Overall, heterogeneity was high (I2 > 95%, p < 0.001) that was most likely caused by geographical area, study design, setting and use of different referral strategies. The pooled proportion of axSpA and PsA among patients referred to the rheumatology outpatient clinic was 19 and 18%, respectively. Although the proportion of diagnosed axSpA patients seemed to increase after the introduction of the ASAS criteria, due to the large heterogeneity our findings should be interpreted with caution.

The impact of different (rheumatoid) arthritis phenotypes on patients' lives.

OBJECTIVES: To compare patient-reported outcome (PRO) domains between three arthritis phenotypes [undifferentiated arthritis (UA), autoantibody-negative RA (RA-) and autoantibody-positive RA (RA+)] at diagnosis, after 2 years and over time. METHODS: All UA (n = 130), RA- (n = 176) and RA+ (n = 331) patients from the tREACH trial, a stratified single-blinded trial with a treat-to-target approach, were used. PRO comparisons between phenotypes at baseline and after 2 years were performed with analysis of variance, while a linear mixed model compared them over time. Effect sizes were weighted against the minimal clinically important differences (MCIDs) for each PRO. RESULTS: RA- patients had a higher disease burden compared with RA+ and UA. At baseline and after 2 years, RA- patients had more functional impairment and a poorer Physical Component Summary (PCS) compared with the other phenotypes, while they only scored worse for general health and morning stiffness duration at baseline. The MCIDs were exceeded at baseline, except for functional ability between RA+ and UA, while after 2 years only the MCID of the PCS was exceeded by RA- compared with UA and RA. After 2 years the PROs of all phenotypes improved, but PROs measuring functioning were still worse compared with the general population, even when patients had low disease activity. CONCLUSION: RA- patients had the highest disease burden of all phenotypes. Although most patients have low disease activity after treatment, all clinical phenotypes still have a similar significant impact on patients' lives, which is mainly physical. Therefore it is important to assess and address PROs in daily practice because of persistent disease burden despite low disease activity. TRIAL REGISTRATION: ISRCTN26791028.

Diagnostic performance of the ACR/EULAR 2010 criteria for rheumatoid arthritis and two diagnostic algorithms in an early arthritis clinic (REACH).

INTRODUCTION: An ACR/EULAR task force released new criteria to classify rheumatoid arthritis at an early stage. This study evaluates the diagnostic performance of these criteria and algorithms by van der Helm and Visser in REACH. METHODS: Patients with symptoms ≤12 months from REACH were used. Algorithms were tested on discrimination, calibration and diagnostic accuracy of proposed cut-points. Two patient sets were defined to test robustness; undifferentiated arthritis (UA) (n=231) and all patients including those without synovitis (n=513). The outcomes evaluated were methotrexate use and persistent disease at 12 months. RESULTS: In UA patients all algorithms had good areas under the curve 0.79, 95% CI 0.73 to 0.83 for the ACR/EULAR criteria, 0.80, 95% CI 0.74 to 0.87 for van der Helm and 0.83, 95% CI 0.77 to 0.88 for Visser. All calibrated well. Sensitivity and specificity were 0.74 and 0.66 for the ACR/EULAR criteria, 0.1 and 1.0 for van der Helm and 0.59 and 0.93 for Visser. Similar results were found in all patients indicating robustness. CONCLUSION: The ACR/EULAR 2010 criteria showed good diagnostic properties in an early arthritis cohort reflecting daily practice, as did the van der Helm and Visser algorithms. All were robust. To promote uniformity and comparability the ACR/EULAR 2010 criteria should be used in future diagnostic studies.