title: Do extra-articular manifestations influence outcome in ankylosing spondylitis? 12-year results from OASIS.
abstract: OBJECTIVE
  To assess in patients with ankylosing spondylitis (AS) whether extra-articular manifestations (EAMs) are associated with worse functioning, worse quality of life (QoL), and more radiographic damage over time.
  
  
  METHODS
  12-year follow-up data from the Outcome in Ankylosing Spondylitis International Study were used, complemented with data on EAMs extracted from medical charts. Functioning was assessed by the BASFI and physical component of the SF-36, QoL by ASQoL and EuroQoL, and radiographic damage by the mSASSS. Generalised estimating equations analyses were made to assess whether EAMs were associated with these outcomes over time.
  
  
  RESULTS
  216 patients were included (154 (71%) men, mean age 43.6 years (SD 12.7), mean symptom duration 20.5 years (SD 11.7), and mean follow-up 8.3 years (SD 4.3). In total, 58 (26.9%) patients had acute anterior uveitis (AAU), 24 (11.1%) inflammatory bowel disease (IBD), and 14 (6.5%) psoriasis. Univariably, IBD was associated with worse BASFI over time (B=1.26, 95%-CI 0.13 to 2.39, p=0.03), but not in a multivariable model. Furthermore, in a multivariable model, IBD was associated with EuroQoL over time (B=2.93, 95%-CI 0.14 to 5.72, p=0.04). Univariably, psoriasis was associated with radiographic damage (B=-7.25, 95%-CI -14.38 to -0.12, p=0.05) and ASQoL (B= -1.94, 95%-CI -3.32 to -0.57, p<0.01) over time, but not in a multivariable model. AAU was not associated with any outcome over time.
  
  
  CONCLUSIONS
  In this longstanding AS cohort, the presence of EAMs was not associated with functional disability, QoL or radiographic damage over time, except for IBD, which was associated with a better EuroQoL.
authors: Department of Medicine, Division of Rheumatology, Maastricht University Medical Center, and School for Public Health and Primary Care (CAPHRI), Maastricht University, Maastricht, the Netherlands. ivette.essers@maastrichtuniversity.nl.
authors: Ivette
authors: I
authors: Essers
authors: Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands.
authors: Sofia
authors: S
authors: Ramiro
authors: Department of Medicine, Division of Rheumatology, Maastricht University Medical Center, and School for Public Health and Primary Care (CAPHRI), Maastricht University, Maastricht, the Netherlands.
authors: Carmen
authors: C
authors: Stolwijk
authors: Department of Medicine, Division of Rheumatology, Maastricht University Medical Center, and School for Public Health and Primary Care (CAPHRI), Maastricht University, Maastricht, the Netherlands.
authors: Marc
authors: M
authors: Blaauw
authors: Department of Clinical Immunology and Rheumatology, Academic Medical Center, Amsterdam; and Department of Rheumatology, Atrium Medical Center, Heerlen, the Netherlands.
authors: Robert
authors: R
authors: Landewé
authors: Department of Rheumatology, Leiden University Medical Center, Leiden, the Netherlands.
authors: Désirée
authors: D
authors: van der Heijde
authors: Department of Rheumatology, Ghent University Hospital and Ghent University, Ghent, Belgium.
authors: Filip
authors: F
authors: van den Bosch
authors: Department of Rheumatology, Paris-Descartes University, Hôpital Cochin, Assistance Publique, Hôpitaux de Paris, INSERM (U1153); Clinical Epidemiology Biostatistics, PRES Sorbonne, Paris-Cité, Paris, France.
authors: Maxime
authors: M
authors: Dougados
authors: Department of Medicine, Division of Rheumatology, Maastricht University Medical Center, and School for Public Health and Primary Care (CAPHRI), Maastricht University, Maastricht, the Netherlands.
authors: Astrid
authors: A
authors: van Tubergen
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000150:complications; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000150:complications; D011788:Quality of Life; D011859:Radiography; D013167:Spondylitis, Ankylosing / Q000150:complications* / Q000000981:diagnostic imaging / Q000523:psychology; D014606:Uveitis, Anterior / Q000150:complications