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. 2022 Feb;8(1):e001955.
doi: 10.1136/rmdopen-2021-001955.

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

Monica Hernandez Alava  1 , Allan Wailoo  2 , Georgios Chrysanthou  3 , Filipe Barcelos  4   5   6 , Floris A van Gaalen  7 , Helena Santos  6   8 , Karen Minde Fagerli  9 , Laura Gago  6   10 , Maria Margarida Cunha  6   11 , Marleen van de Sande  12   13 , Maura C Couto  6   14 , Miguel Bernardes  6   15   16 , Roberta Ramonda  17 , Sofia Exarchou  18 , Pedro D Carvalho  19   20   21 , Desirée van der Heijde  22 , Pedro M Machado  23   24   25
Affiliations

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

Monica Hernandez Alava et al. RMD Open. 2022 Feb.

Abstract

Objectives: To estimate the relationship between EQ5D (three levels, 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).

Methods: An electronic, prospective, Portuguese, nationwide, rheumatic disease register (Reuma.pt) 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 cohort provided data from 344 patients (1405 observations) in four European countries and was used for validation. A previously published model of BASDAI/Bath Ankylosing Spondylitis Functional Index (BASFI) was also used to generate predicted EQ5D scores and model performance compared.

Results: 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 were 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.

Conclusions: 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 with BASDAI but this has only a marginal impact.

Keywords: ankylosing; economics; patient reported outcome measures; spondylitis.

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Conflict of interest statement

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.

Figures

Figure 1
Figure 1
Distribution of EQ5D-3L in the Reuma.pt registry.
Figure 2
Figure 2
Mean EQ5D by ASDAS score, predicted versus observed values for the ASDAS only model. ASDAS, Ankylosing Spondylitis Disease Activity Score.
Figure 3
Figure 3
EQ5D by mean BASFI, predicted versus observed values for the ASDAS and BASFI model. ASDAS, Ankylosing Spondylitis Disease Activity Score; BASFI, Bath Ankylosing Spondylitis Functional Index.
Figure 4
Figure 4
EQ5D by mean BASFI, predicted versus observed values for the BASFI/BASDAI model. BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index.
Figure 5
Figure 5
EQ5D by mean BASDAI, predicted versus observed values for the BASFI/BASDAI model. BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index.
See this image and copyright information in PMC

References

    1. Ara RM, Reynolds AV, Conway P. The cost-effectiveness of etanercept in patients with severe ankylosing spondylitis in the UK. Rheumatology 2007;46:1338–44. 10.1093/rheumatology/kem133 - DOI - PubMed
    1. Mlcoch T, Sedova L, Stolfa J, et al. . Mapping the relationship between clinical and quality-of-life outcomes in patients with ankylosing spondylitis. Expert Rev Pharmacoecon Outcomes Res 2017;17:203–11. 10.1080/14737167.2016.1200468 - DOI - PubMed
    1. Wailoo A, Hernández M, Philips C, et al. . Modeling health state utility values in ankylosing spondylitis: comparisons of direct and indirect methods. Value Health 2015;18:425–31. 10.1016/j.jval.2015.02.016 - DOI - PubMed
    1. Machado P, Landewé R. Spondyloarthritis: is it time to replace BASDAI with ASDAS? Nat Rev Rheumatol 2013;9:388–90. 10.1038/nrrheum.2013.93 - DOI - PubMed
    1. Machado PMMC, Landewé RBM, van der Heijde DM. Endorsement of definitions of disease activity states and improvement scores for the ankylosing spondylitis disease activity score: results from OMERACT 10. J Rheumatol 2011;38:1502–6. 10.3899/jrheum.110279 - DOI - PubMed

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