Objectives To investigate the prevalence of axial spondyloarthritis (axSpA) in patients with chronic back pain (CBP) of less than 2 years (2y) duration referred to the rheumatologist, the... Show moreObjectives To investigate the prevalence of axial spondyloarthritis (axSpA) in patients with chronic back pain (CBP) of less than 2 years (2y) duration referred to the rheumatologist, the development of diagnosis over time, and patient characteristics of those developing definite (d-)axSpA over 2y. Methods We analysed the 2y data from SPondyloArthritis Caught Early, a European cohort of patients (<45 years) with CBP (>= 3 months, <= 2y) of unknown origin. The diagnostic workup comprised evaluation of clinical SpA features, acute phase reactants, HLA-B27, radiographs and MRI (sacroiliac joints and spine), with repeated assessments. At each visit (baseline, 3 months, 1y and 2y), rheumatologists reported a diagnosis of axSpA or non-axSpA with level of confidence (LoC; 0-not confident at all to 10-very confident). Main outcome: axSpA diagnosis with LoC >= 7 (d-axSpA) at 2y. Results In 552 patients with CBP, d-axSpA was diagnosed in 175 (32%) at baseline and 165 (30%) at 2y. Baseline diagnosis remained rather stable: at 2y, baseline d-axSpA was revised in 5% of patients, while 8% 'gained' d-axSpA. Diagnostic uncertainty persisted in 30%. HLA-B27+ and baseline sacroiliitis imaging discriminated best 2y-d-axSpA versus 2y-d-non-axSpA patients. Good response to non-steroidal anti-inflammatory drugs and MRI-sacroiliitis most frequently developed over follow-up in patients with a new d-axSpA diagnosis. Of the patients who developed MRI-sacroiliitis, 7/8 were HLA-B27+ and 5/8 male. Conclusion A diagnosis of d-axSpA can be reliably made in nearly one-third of patients with CBP referred to the rheumatologist, but diagnostic uncertainty may persist in 5%-30% after 2y. Repeated assessments yield is modest, but repeating MRI may be worthwhile in male HLA-B27+ patients. Show less
Ortolan, A.; Ramiro, S.; Ramonda, R.; Heijde, D. van der 2022
Objectives: The alternative ASDAS (altASDAS) is an index that can be used when patient global assessment is unavailable. Our aim was to test the truth and discrimination aspects according to... Show moreObjectives: The alternative ASDAS (altASDAS) is an index that can be used when patient global assessment is unavailable. Our aim was to test the truth and discrimination aspects according to OMERACT filter 2.0 of the altASDAS in an external cohort. Methods: Cohorts from the COAST trials of ixekizumab (COAST-V, -W, -X; 16-week primary endpoint) enrolling radiographic/non-radiographic axial SpA patients were pooled. The ASDAS [original formula with patient global assessment (PGA)] and altASDAS were calculated. Truth was assessed by agreement with the continuous ASDAS [intraclass correlation coefficients (ICCs)] and ASDAS disease activity (DA) states (weighted kappa), Bland-Altman plots [mean difference (MD) and 95% limits of agreement (LoA)] and Pearson's correlations between altASDAS/ASDAS and other constructs. Discrimination was tested by the ability of altASDAS to distinguish high/low DA according to nocturnal pain >6/10 as an external anchor and agreement (kappa) with ASDAS in major improvement (MI) and clinically important improvement (CII). Results: A total of 958 patients were included. For truth, agreement with ASDAS was very good (ICC = 0.99, kappa = 0.91), MD with ASDAS was 0.03 (95% LoA -0.31-0.24) and correlation coefficients of altASDAS with related constructs were within a prespecified 0.3-wide band around those between ASDAS and the same construct. For discrimination, the altASDAS discriminated between DA states and agreed with ASDAS response (kappa MI = 0.91, CII = 0.93). Conclusions: The altASDAS was truthful and discriminative in an external cohort and as such has been fully validated to be used in cases when PGA is unavailable. Show less
Bakker, P.A.C.; Ramiro, S.; Ez-Zaitouni, Z.; Lunteren, M. van; Berg, I.J.; Landewe, R.; ... ; Heijde, D. van der 2019
