{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,11]],"date-time":"2025-09-11T17:25:57Z","timestamp":1757611557775,"version":"3.44.0"},"reference-count":28,"publisher":"BMJ","issue":"4","license":[{"start":{"date-parts":[[2024,12,10]],"date-time":"2024-12-10T00:00:00Z","timestamp":1733788800000},"content-version":"unspecified","delay-in-days":9,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"name":"Section for Biostatistics and Evidence-Based Research, the Parker Institute, Bispebjerg"},{"DOI":"10.13039\/100001275","name":"Oak Foundation","doi-asserted-by":"publisher","award":["OCAY-18-774-OFIL"],"award-info":[{"award-number":["OCAY-18-774-OFIL"]}],"id":[{"id":"10.13039\/100001275","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["RMD Open"],"accepted":{"date-parts":[[2024,11,4]]},"published-print":{"date-parts":[[2024,12]]},"abstract":"<jats:sec>\n                  <jats:title>Objectives<\/jats:title>\n                  <jats:p>To compare the construct validity, including discrimination between known groups, of three pain and three morning stiffness (MS) measurement instruments.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>Patients with radiographic axial spondyloarthritis with 8-year data from the Outcome in Ankylosing Spondylitis International Study cohort were assessed cross-sectionally. Three instruments for pain and three for MS, all self-reported and scored 0\u201310, were compared. Construct validity was evaluated by testing (1) hypothesis of correlations\u2019 strength and (2) discrimination between known groups using standardised mean differences (SMD) across external constructs. Influence of contextual factors (CFs) on SMDs was investigated.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>Of 85 patients, mean age was 54 (SD 11), mean symptom duration 31 (11) years, 71% males. All six instruments showed a good construct validity by fulfilling &gt;75% of the hypotheses for the strength of correlation. Neck\/back\/hip pain (Bath Ankylosing Spondylitis Disease Activity Index-Question 2, BASDAI-Q2) and total back pain had higher SMDs compared with back pain at night across all between-group comparisons, with BASDAI-Q2 performing mostly slightly better (eg, SMD for external construct Axial Spondyloarthritis Disease Activity Score (ASDAS; \u22652.1\u2009vs &lt;2.1): 1.87 (BASDAI-Q2) vs 1.56 (total back pain) vs 1.07 (back pain at night)). MS-severity and severity\/duration had higher SMDs across all external constructs (with MS-severity slightly better), while MS-duration performed worse (eg, SMD external construct ASDAS: 1.51 (MS-severity) and 1.39 (MS-severity\/duration) vs 1.16 (MS-duration)). Influence of CFs on known group discrimination was limited.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>The recommended Assessment of SpondyloArthritis international Society Core Outcome Set (ASAS-COS) pain measurement instrument total back pain BASDAI-Q2 has the best known group discrimination. For MS, the ASAS-COS stiffness measure (MS-severity\/duration) performs well although MS-severity even slightly better. Known group discrimination is overall stable across CFs.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1136\/rmdopen-2024-004775","type":"journal-article","created":{"date-parts":[[2024,12,10]],"date-time":"2024-12-10T19:30:57Z","timestamp":1733859057000},"page":"e004775","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Comparing the construct validity of measurement instruments for pain and stiffness in patients with axial spondyloartwhritis: cross-sectional analysis in the OASIS cohort"],"prefix":"10.1136","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9336-0416","authenticated-orcid":false,"given":"Dafne","family":"Capelusnik","sequence":"first","affiliation":[{"name":"Care and Public Health Research Institute (CAPHRI), Maastricht University, Maastricht, Netherlands"},{"name":"Rheumatology, Tel Aviv Sourasky Medical Center\u2013Ichilov, Tel Aviv, Israel"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6847-3726","authenticated-orcid":false,"given":"Elena","family":"Nikiphorou","sequence":"additional","affiliation":[{"name":"Centre for Rheumatic Diseases, King\u2019s College Hospital Charity, London, UK"},{"name":"Rheumatology, King\u2019s College Hospital Charity, London, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0682-9533","authenticated-orcid":false,"given":"Annelies","family":"Boonen","sequence":"additional","affiliation":[{"name":"Care and Public Health Research Institute (CAPHRI), Maastricht University, Maastricht, Netherlands"},{"name":"Department of Rheumatology, Maastricht University Medical Centre+, Maastricht, Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Robin","family":"Christensen","sequence":"additional","affiliation":[{"name":"Section for Biostatistics and Evidence-Based Research, Bispebjerg Hospital, Kobenhavn, Denmark"},{"name":"Clinical Research, Odense University Hospital, Odense, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5781-158X","authenticated-orcid":false,"given":"D\u00e9sir\u00e9e","family":"van der Heijde","sequence":"additional","affiliation":[{"name":"Rheumatology, Leiden University Medical Center, Leiden, Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0577-6620","authenticated-orcid":false,"given":"Robert","family":"Landew\u00e9","sequence":"additional","affiliation":[{"name":"Clinical Immunology and Rheumatology, Amsterdam University Medical Centres, Amsterdam, Netherlands"},{"name":"Rheumatology, Zuyderland Medical Centre, Sittard-Geleen, Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8477-0683","authenticated-orcid":false,"given":"Astrid","family":"van Tubergen","sequence":"additional","affiliation":[{"name":"Care and Public Health Research Institute (CAPHRI), Maastricht University, Maastricht, Netherlands"},{"name":"Department of Rheumatology, Maastricht University Medical Centre+, Maastricht, Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8899-9087","authenticated-orcid":false,"given":"Sofia","family":"Ramiro","sequence":"additional","affiliation":[{"name":"Rheumatology, Leiden University Medical Center, Leiden, Netherlands"},{"name":"Department of Rheumatology, Zuyderland Medical Centre Heerlen, Heerlen, Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2024,12,10]]},"reference":[{"key":"2025090313330693000_10.4.e004775.1","doi-asserted-by":"publisher","DOI":"10.1136\/annrheumdis-2022-222747"},{"key":"2025090313330693000_10.4.e004775.2","first-page":"2286","article-title":"A new approach to defining disease status in ankylosing spondylitis: the Bath Ankylosing Spondylitis Disease Activity Index","volume":"21","author":"Garrett","year":"1994","journal-title":"J Rheumatol"},{"key":"2025090313330693000_10.4.e004775.3","doi-asserted-by":"publisher","DOI":"10.1136\/ard.2008.104018"},{"key":"2025090313330693000_10.4.e004775.4","doi-asserted-by":"crossref","first-page":"1320","DOI":"10.1016\/j.semarthrit.2021.08.011","article-title":"The evolution of instrument selection for inclusion in core outcome sets at OMERACT: Filter 2.2","volume":"51","author":"Maxwell","year":"2021","journal-title":"Semin Arthritis Rheum"},{"key":"2025090313330693000_10.4.e004775.5","doi-asserted-by":"publisher","DOI":"10.1016\/j.jclinepi.2010.02.006"},{"key":"2025090313330693000_10.4.e004775.6","doi-asserted-by":"crossref","first-page":"1117","DOI":"10.1016\/j.semarthrit.2021.07.014","article-title":"OMERACT Filter 2.1 instrument selection for physical function domain in psoriatic arthritis: Provisional endorsement for HAQ-DI and SF-36 PF","volume":"51","author":"Leung","year":"2021","journal-title":"Semin Arthritis Rheum"},{"key":"2025090313330693000_10.4.e004775.7","doi-asserted-by":"publisher","DOI":"10.1136\/ard.2008.100826"},{"key":"2025090313330693000_10.4.e004775.8","doi-asserted-by":"crossref","first-page":"601","DOI":"10.1016\/j.semarthrit.2021.03.013","article-title":"OMERACT consensus-based operational definition of contextual factors in rheumatology clinical trials: A mixed methods study","volume":"51","author":"Nielsen","year":"2021","journal-title":"Semin Arthritis Rheum"},{"key":"2025090313330693000_10.4.e004775.9","doi-asserted-by":"publisher","DOI":"10.1136\/annrheumdis-2020-217895"},{"key":"2025090313330693000_10.4.e004775.10","first-page":"980","article-title":"Relative value of erythrocyte sedimentation rate and C-reactive protein in assessment of disease activity in ankylosing spondylitis","volume":"26","author":"Spoorenberg","year":"1999","journal-title":"J Rheumatol"},{"key":"2025090313330693000_10.4.e004775.11","first-page":"2281","article-title":"A new approach to defining functional ability in ankylosing spondylitis: the development of the Bath Ankylosing Spondylitis Functional Index","volume":"21","author":"Calin","year":"1994","journal-title":"J Rheumatol"},{"key":"2025090313330693000_10.4.e004775.12","first-page":"1694","article-title":"Defining spinal mobility in ankylosing spondylitis (AS)","volume":"21","author":"Jenkinson","year":"1994","journal-title":"Bath AS Metrology Index J Rheumatol"},{"key":"2025090313330693000_10.4.e004775.13","doi-asserted-by":"publisher","DOI":"10.1016\/0168-8510(90)90421-9"},{"key":"2025090313330693000_10.4.e004775.14","doi-asserted-by":"publisher","DOI":"10.1136\/ard.62.1.20"},{"key":"2025090313330693000_10.4.e004775.15","doi-asserted-by":"publisher","DOI":"10.1136\/bmj.306.6890.1437"},{"key":"2025090313330693000_10.4.e004775.16","doi-asserted-by":"publisher","DOI":"10.1093\/rheumatology\/key128"},{"key":"2025090313330693000_10.4.e004775.17","doi-asserted-by":"publisher","DOI":"10.4236\/jwarp.2015.77047"},{"key":"2025090313330693000_10.4.e004775.18","doi-asserted-by":"crossref","DOI":"10.1136\/bmj.k4817","article-title":"When continuous outcomes are measured using different scales: guide for meta-analysis and interpretation","volume":"364","author":"Murad","year":"2019","journal-title":"BMJ"},{"key":"2025090313330693000_10.4.e004775.19","doi-asserted-by":"publisher","DOI":"10.1016\/j.jclinepi.2021.03.009"},{"key":"2025090313330693000_10.4.e004775.20","doi-asserted-by":"publisher","DOI":"10.1136\/ard.2008.094870"},{"key":"2025090313330693000_10.4.e004775.21","first-page":"S","article-title":"The ASAS Health Index (ASAS HI) - a new tool to assess the health status of patients with spondyloarthritis","volume":"32","author":"Kiltz","year":"2014","journal-title":"Clin Exp Rheumatol"},{"key":"2025090313330693000_10.4.e004775.22","doi-asserted-by":"publisher","DOI":"10.3899\/jrheum.220244"},{"key":"2025090313330693000_10.4.e004775.23","doi-asserted-by":"publisher","DOI":"10.1136\/annrheumdis-2018-213463"},{"key":"2025090313330693000_10.4.e004775.24","doi-asserted-by":"crossref","first-page":"2043","DOI":"10.1093\/rheumatology\/keab638","article-title":"Individual-level and country-level socio-economic factors and health outcomes in spondyloarthritis: analysis of the ASAS-perSpA study","volume":"61","author":"Capelusnik","year":"2022","journal-title":"Rheumatology (Oxford)"},{"key":"2025090313330693000_10.4.e004775.25","doi-asserted-by":"publisher","DOI":"10.1136\/annrheumdis-2018-214259"},{"key":"2025090313330693000_10.4.e004775.26","doi-asserted-by":"crossref","unstructured":"Capelusnik D , Ramiro S , Nikiphorou E , et al . Thresholds for unacceptable work state in radiographic axial Spondyloarthritis of four presenteeism and two clinical outcome measurement instruments. Rheumatology (Oxford) 2024.:keae033. doi:10.1093\/rheumatology\/keae033","DOI":"10.1093\/rheumatology\/keae033"},{"key":"2025090313330693000_10.4.e004775.27","doi-asserted-by":"crossref","DOI":"10.1136\/rmdopen-2019-001108","article-title":"Characteristics and burden of disease in patients with radiographic and non-radiographic axial Spondyloarthritis: a comparison by systematic literature review and meta-analysis","volume":"5","author":"L\u00f3pez-Medina","year":"2019","journal-title":"RMD Open"},{"key":"2025090313330693000_10.4.e004775.28","doi-asserted-by":"crossref","unstructured":"Navarro-Comp\u00e1n V , Benavent D , Capelusnik D , et al . ASAS consensus definition of early axial spondyloarthritis. Ann Rheum Dis 2023;ard\u20132023. doi:10.1136\/ard-2023-224232","DOI":"10.1136\/annrheumdis-2023-eular.697"}],"container-title":["RMD Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/rmdopen-2024-004775","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,9,3]],"date-time":"2025-09-03T20:33:15Z","timestamp":1756931595000},"score":1,"resource":{"primary":{"URL":"https:\/\/rmdopen.bmj.com\/lookup\/doi\/10.1136\/rmdopen-2024-004775"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,12]]},"references-count":28,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2024,12,10]]},"published-print":{"date-parts":[[2024,12]]}},"alternative-id":["10.1136\/rmdopen-2024-004775"],"URL":"https:\/\/doi.org\/10.1136\/rmdopen-2024-004775","relation":{},"ISSN":["2056-5933"],"issn-type":[{"type":"electronic","value":"2056-5933"}],"subject":[],"published":{"date-parts":[[2024,12]]}}}