Predictive validity of the ASAS classification criteria for axial and peripheral spondyloarthritis after follow-up in the ASAS cohort: a final analysis

Alexandre Sepriano, Robert Landewé, Désirée van der Heijde, Joachim Sieper, Nurullah Akkoc, Jan Brandt, Jürgen Braun, Eduardo Collantes-Estevez, Maxime Dougados, Oliver Fitzgerald, Feng Huang, Jieruo Gu, Yesim Kirazli, Walter P Maksymowych, Helena Marzo-Ortega, Ignazio Olivieri, Salih Ozgocmen, Euthalia Roussou, Salvatore Scarpato, Inge J SørensenRafael Valle-Oñate, Filip Van den Bosch, Irene van der Horst-Bruinsma, Ulrich Weber, James Wei, Martin Rudwaleit, ASAS

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

OBJECTIVE: To establish the predictive validity of the Assessment of SpondyloArthritis international Society (ASAS) spondyloarthritis (SpA) classification criteria.

METHODS: 22 centres (N=909 patients) from the initial 29 ASAS centres (N=975) participated in the ASAS-cohort follow-up study. Patients had either chronic (>3 months) back pain of unknown origin and age of onset below 45 years (N=658) or peripheral arthritis and/or enthesitis and/or dactylitis (N=251). At follow-up, information was obtained at a clinic visit or by telephone. The positive predictive value (PPV) of the baseline classification by the ASAS criteria was calculated using rheumatologist's diagnosis at follow-up as external standard.

RESULTS: In total, 564 patients were assessed at follow-up (345 visits; 219 telephone) with a mean follow-up of 4.4 years (range: 1.9; 6.8) and 70.2% received a SpA diagnosis by the rheumatologist. 335 patients fulfilled the axial SpA (axSpA) or peripheral SpA (pSpA) criteria at baseline and of these, 309 were diagnosed SpA after follow-up (PPV SpA criteria: 92.2%). The PPV of the axSpA and pSpA criteria was 93.3% and 89.5%, respectively. The PPV for the 'clinical arm only' was 88.0% and for the 'clinical arm'±'imaging arm' 96.0%, for the 'imaging arm only' 86.2% and for the 'imaging arm'+/-'clinical arm' 94.7%. A series of sensitivity analyses yielded similar results (range: 85.1-98.2%).

CONCLUSIONS: The PPV of the axSpA and pSpA criteria to forecast an expert's diagnosis of 'SpA' after more than 4 years is excellent. The 'imaging arm' and 'clinical arm' of the axSpA criteria have similar predictive validity and are truly complementary.

Original languageEnglish
Pages (from-to)1034-42
Number of pages9
JournalAnnals of the Rheumatic Diseases
Volume75
Issue number6
DOIs
Publication statusPublished - Jun 2016

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