• Ann. Rheum. Dis. · Mar 2020

    What is axial spondyloarthritis? A latent class and transition analysis in the SPACE and DESIR cohorts.

    • Alexandre Sepriano, Sofia Ramiro, Désirée van der Heijde, Floris van Gaalen, Pierre Hoonhout, Anna Molto, Alain Saraux, Roberta Ramonda, Maxime Dougados, and Robert Landewé.
    • Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands.
    • Ann. Rheum. Dis. 2020 Mar 1; 79 (3): 324-331.

    ObjectivesTo gain expert-judgement-free insight into the Gestalt of axial spondyloarthritis (axSpA), by investigating its 'latent constructs' and to test how well these latent constructs fit the Assessment of SpondyloArthritis international Society (ASAS) classification criteria.MethodsTwo independent cohorts of patients with early onset chronic back pain (SPondyloArthritis Caught Early (SPACE)) or inflammatory back pain (IBP) (DEvenir des Spondylarthopathies Indifférenciées Récentes (DESIR)) were analysed. Latent class analysis (LCA) was used to estimate the (unobserved) potential classes underlying axSpA. The best LCA model groups patients into clinically meaningful classes with best fit. Each class was labelled based on most prominent features. Percentage fulfilment of ASAS axSpA, peripheral SpA (pSpA) (ignoring IBP) or both classification criteria was calculated. Five-year data from DESIR were used to perform latent transition analysis (LTA) to examine if patients change classes over time.ResultsSPACE (n=465) yielded four discernible classes: 'axial' with highest likelihood of abnormal imaging and HLA-B27 positivity; 'IBP+peripheral' with 100% IBP and dominant peripheral symptoms; 'at risk' with positive family history and HLA-B27 and 'no SpA' with low likelihood for each SpA feature. LCA in DESIR (n=576) yielded similar classes, except for the 'no-SpA'. The ASAS axSpA criteria captured almost all (SPACE: 98%; DESIR: 93%) 'axial' patients, but the 'IBP+peripheral' class was only captured well by combining the axSpA and pSpA criteria (SPACE: 78%; DESIR: 89%). Only 4% of 'no SpA' patients fulfilled the axSpA criteria in SPACE. LTA suggested that 5-year transitions across classes were unlikely (11%).ConclusionThe Gestalt of axSpA comprises three discernible entities, only appropriately captured by combining the ASAS axSpA and pSpA classification criteria. It is questionable whether some patients with 'axSpA at risk' will ever develop axSpA.© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.

      Pubmed     Full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…