WORKING GROUP NAME: Axial Spondyloarthritis

What is Axial Spondylitis (Axial SpA)?

Axial SpA is a form of inflammatory arthritis that most commonly affects the joints of the spine and pelvis. Common features of spondyloarthritis include inflammatory back pain back pain, as well as pain and inflammation in the peripheral joints, the digestive tract or eyes. Nowadays, patients with axSpA are usually classified in two groups: i) Patients with radiographic axSpA also known as ankylosing spondylitis (AS), who have developed substantial damage of the pelvis visible on radiographs, and ii) Patients with non-radiographic axSpA, who do not have damage visible on radiographs but do have other symptoms specific for axSpA.

How is someone with Axial SpA treated?

The management of axial SpA include pharmacological (e.g. NSAIDs and biological drugs) and non-pharmacological (e.g. physiotherapy, exercise) treatment, commonly used in combination to treat patients.

Are these treatments known to work?

During the last decades, new efficacious drugs have been developed to treat patients with axial SpA. These drugs have shown to be efficacious to reduce symptoms and signs of the disease in many patients. Nevertheless, these drugs are not efficacious in all patients with axial SpA and therefore it is necessary to continue doing research and developing new drugs for this disease. Anytime that a new drug is developed, its efficacy and safety need to be investigated through specific studies named as clinical trials. However, reporting of consistent outcomes in trials has been an issue dating back to the 1990s. In 1995 ASAS-OMERACT formed a working group to get to grips with the standardisation of outcomes and developed the core domain set for ankylosing spondylitus trials:



So, what’s needed now?

The current ASAS-OMERACT core set for ankylosing spondylitis was a milestone. However, this core set is now 25 years old and incorporates only very minor adaptations during this long period, while major advances in the field of core domains methodology and treatment options for axial SpA have occurred which may impact the internationally agreed upon and endorsed core outcome set.

Among the main advances in outcomes in the field of axial SpA, is the use of magnetic resonance, the development of the ASDAS (Ankylosing Spondylitis Disease Activity Score), validated enthesitis scores, the ASAS-health index and the ASAS-flare definition.

The periodical review of a core set is important to ensure that the outcomes are still relevant and important, to allow adding new outcomes, and engaging further stakeholders as appropriate. In this sense, an important aspect nowadays is that the core set should be applicable to the entire spectrum of axial SpA and not be limited to ankylosing spondylitis.

What stage is the working group at with their update?

The update of the ASAS-OMERACT core set for ankylosing spondylitis started in January 2018. The preliminary results for the domains to be included within the core set were presented in January during the ASAS 2019 workshop, and will be presented for a vote at the ASAS 2020 and OMERACT 2020 meetings. After this, the group will continue working on the selection of the instruments to be included within the core set. The project is being performed in accordance with OMERACT processes, guidelines and spirit-

To update the ASAS/OMERACT core set with the minimum number of domains that should be measured in clinical studies for ankylosing spondylitis, the information collected in the (ICF) Core Set for ankylosing spondylitis was employed


Désirée van der Heijde:

Victoria Navarro-Compán:

Annelies Boonen:

Philip Mease:

OMERACT 2020 Workshop Session

Friday April 24th 8:30 am – 11:00am



How well are the ASAS/OMERACT Core Outcome Sets for Ankylosing Spondylitis implemented in randomized clinical trials? A systematic literature review


Endorsement of Definitions of Disease Activity States and Improvement Scores for the Ankylosing Spondylitis Disease Activity Score_ Results from OMERACT 10

OMERACT Magnetic Resonance Imaging Initiative on Structural and Inflammatory Lesions in Ankylosing Spondylitis


Selection of a Method for Scoring Radiographs for AS Clinical Trials, by the Assessment in AS Working Group and OMERACT 


Which Domains Should Be lncluded in a Core Set for Endpoints in AS? Introduction to the AS Module of OMERACT IV

Selection of Instruments in the Core Set for DC-ART, SMARD, Physical Therapy, and Clinical Record Keeping in AS. Progress Report of the ASAS Working Group

Comparison of the Dougados Functional Index and the BASFI. A Literature Review

A Comparative Study of the Usefulness of the BASFI and the Dougados Functional Index in the Assessment of AS

Validity Aspects of ESR and CRP in AS: A Literature Review

Clinical Relevance of C-Reactive Protein in Axial Involvement of AS

Outcome Variables in AS: Evaluation of Their Relevance and Discriminant Capacity

Relative Value of ESR and CRP in Assessment of Disease Activity in AS

Plain Radiographs as an Outcome Measure in Ankylosing Spondylitis

A New Dimension to Outcome Application of The Bath Ankylosing Spondylitis Radiology Index

Stoke Ankylosing Spondylitis Spine Score

Radiological Scoring Methods in AS Reliability and Sensitivity to Change Over One Year

AS: Plenary Discussion and Results of Voting on Selection of Domains and Some Specific Instruments


Désirée van der Heijde      Victoria Navarro-Compán

Annelies Boonen      Philip Mease

Robert Landewé      Maxime Dougados

Uta Kiltz      Anne Boel


  • Wilson Bautista
  • Ana Belén Romero
  • Anne Boel
  • Annelies Boonen
  • Hilde Carlier
  • Pravina Chiowchanwisawakit
  • Hanne Dagfinrud
  • Natasha de Peyrecave
  • Maxime Dougados
  • Philip Mease
  • Bassel El-Zorkany
  • Karl Gaffney
  • Marco Garrido
  • Lianne Gensler
  • Nigel Haroon
  • Merryn Jongkees
  • Uta Klitz
  • Yu Heng Kwan
  • Robert Landewé
  • Désirée van der Heijde
  • Pedro Machado
  • Victoria Navarro-Compán
  • Mikhail Propoponov
  • Sofia Ramiro
  • Liesbeth Rook
  • In-Ho Song
  • Salima van Weel
  • Peter Tugwell