%0 Journal Article %A Alexandre Sepriano %A Robert Landewé %A Désirée van der Heijde %A Joachim Sieper %A Nurullah Akkoc %A Jan Brandt %A Jürgen Braun %A Eduardo Collantes-Estevez %A Maxime Dougados %A Oliver Fitzgerald %A Feng Huang %A Jieruo Gu %A Yesim Kirazli %A Walter P Maksymowych %A Helena Marzo-Ortega %A Ignazio Olivieri %A Salih Ozgocmen %A Euthalia Roussou %A Salvatore Scarpato %A Inge J Sørensen %A Rafael Valle-Oñate %A Filip Van den Bosch %A Irene van der Horst-Bruinsma %A Ulrich Weber %A James Wei %A Martin Rudwaleit %T Predictive validity of the ASAS classification criteria for axial and peripheral spondyloarthritis after follow-up in the ASAS cohort: a final analysis %D 2016 %R 10.1136/annrheumdis-2015-208730 %J Annals of the Rheumatic Diseases %P 1034-1042 %V 75 %N 6 %X 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. %U https://ard.bmj.com/content/annrheumdis/75/6/1034.full.pdf