Measuring quality of life of patients with axial spondyloarthritis for economic evaluation

Monica Hernández Alava, Allan Wailoo, Georgios Chrysanthou, Filipe Barcelos, Floris Alexander van Gaalen, Helena Santos, Karen Fagerli, Laura Gago, Maria Margarida Cunha, Marleen van de Sande, Maura Couto, Miguel Bernardes, Roberta Ramonda, Sofia Exarchou, Pedro Carvalho, van der Heijde Désirée, Pedro Machado

Research output: Contribution to journalArticlepeer-review

2 Citations (SciVal)



To estimate the relationship between EQ5D (3-level, UK version) and the Ankylosing Spondylitis Disease Activity Score (ASDAS) for use in the economic evaluation of health technologies for people with axial spondyloarthritis (axSpA). To compare against the relationship with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI).


An electronic, prospective, Portuguese, nationwide, rheumatic disease register ( provided data on 1140 patients (5483 observations) with a confirmed diagnosis of axSpA. We estimated models of EQ5D as a function of ASDAS, alone or in combination with measures of functional impairment, using bespoke mixture models which reflect the complex distributional features of EQ5D. The SPondyloArthritis Caught Early (SPACE) cohort provided data from 344 patients (1405 observations) in four European countries and was used for validation. A previously published model of BASDAI/BASFI was also used to generate predicted EQ5D scores and model performance compared.


A non-linear relationship exists between EQ5D from ASDAS. The final model included ASDAS, ASDAS-squared, age and age-squared and demonstrated close fit in both datasets except where data was sparse for patients with very high levels of disease activity (ASDAS >4). This finding held in the validation dataset. Models that included BASFI improved model fit. The ASDAS based models fit the data marginally less well than models using BASDAI.


Mapping models linking ASDAS to EQ5D allow results from clinical studies to be used in economic evaluation of health technologies with confidence. There is some loss of information compared to BASDAI but this has only a marginal impact.
Original languageEnglish
Article numbere001955
JournalRMD Open
Issue number1
Early online date17 Feb 2022
Publication statusPublished - 17 Feb 2022

Bibliographical note

Funding Information:
Funding PMM is supported by the National Institute for Health Research (NIHR), University College London Hospitals (UCLH) and Biomedical Research Centre (BRC).

Funding Information:
Competing interests MvdS has received consulting fees/speaker’s fees/research grants from Novartis, UCB, Abbvie, Janssen, Eli Lilly and MSD. FAvG has received grants from Stichting vrienden van Sole Mio, Stichting ASAS, Jacobus Stichting, Novartis and UCB, and consulting fees from Novartis, Eli Lilly, MSD, AbbVie and Bristol Myers Squibb. MB has received consulting/speaker’s fees from AbbVie, Eli Lilly, Janssen and Novartis. RR has received consulting/speaker’s fees from AbbVie, Eli Lilly, Janssen, MSD, Novartis, Pfizer, and UCB Pharma. SE has received consulting fees from AbbVie, Janssen and Novartis. DvdH has received consulting fees from AbbVie, Amgen, Astellas, AstraZeneca, Bayer, BMS, Boehringer Ingelheim, Celgene, Cyxone, Daiichi, Eisai, Galapagos, Gilead, Glaxo-Smith-Kline, Janssen, Lilly, Merck, Novartis, Pfizer, Regeneron, Roche, Sanofi, Takeda, UCB Pharma and serves as director of Imaging Rheumatology bv. PMM has received consulting/ speaker’s fees from AbbVie, BMS, Celgene, Eli Lilly, Galapagos, Janssen, MSD, Novartis, Orphazyme, Pfizer, Roche and UCB Pharma.

Publisher Copyright:
© 2022 Author(s) (or their employer(s)). Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.


  • ankylosing
  • economics
  • patient reported outcome measures
  • spondylitis

ASJC Scopus subject areas

  • Immunology and Allergy
  • Rheumatology
  • Immunology


Dive into the research topics of 'Measuring quality of life of patients with axial spondyloarthritis for economic evaluation'. Together they form a unique fingerprint.

Cite this