{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T10:34:50Z","timestamp":1791974090182,"version":"4.4.0"},"reference-count":30,"publisher":"Wiley","issue":"12","license":[{"start":{"date-parts":[[2019,11,13]],"date-time":"2019-11-13T00:00:00Z","timestamp":1573603200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Int J of Rheum Dis"],"published-print":{"date-parts":[[2019,12]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Introduction<\/jats:title><jats:p>The Ankylosing Spondylitis Disease Activity Score with C\u2010reactive protein (ASDAS\u2010CRP) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) are commonly used instruments for measuring disease activity. However, few studies have assessed their psychometric properties in patients with axial spondyloarthritis (axSpA). We aimed to assess the validity and reliability of ASDAS\u2010CRP and BASDAI in patients with axSpA in Singapore.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Cross\u2010sectional data from 280 patients with axSpA from a dedicated axSpA clinic in a Singapore tertiary referral hospital from 2011 to 2019 were used. Internal consistency was assessed using Cronbach's alpha. Construct validity was assessed through 12 <jats:italic>a priori<\/jats:italic> hypotheses by correlation of overall ASDAS\u2010CRP and BASDAI score with other patient\u2010reported outcomes measures (PROMs). Structural validity was evaluated via confirmatory factor analysis using maximum\u2010likelihood method, where Comparative Fit Index (CFI) &gt;0.95, Tucker\u2010Lewis Index (TLI) &gt;0.95, Root Mean Square Error of Approximation (RMSEA) &lt;0.06 and Standardized Root Mean Residuals (SRMR) &lt;0.08 were indicative of good fit.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Among 280 patients (78.2% Male; 92.5% Chinese), ASDAS\u2010CRP showed poor internal consistency of 0.33, while BASDAI showed high internal consistency of 0.87. Convergent and divergent construct validity were demonstrated by fulfillment of 11 out of 12 <jats:italic>a priori<\/jats:italic> hypotheses when ASDAS\u2010CRP and BASDAI were compared with other PROMs. Our proposed ASDAS\u2010CRP and BASDAI model showed good fit for a 1\u2010factor structure respectively (CFI\u00a0=\u00a00.993, TLI\u00a0=\u00a00.984, RMSEA\u00a0=\u00a00.036, SRMR\u00a0=\u00a00.026 for ASDAS\u2010CRP; CFI\u00a0=\u00a00.993, TLI\u00a0=\u00a00.985, RMSEA\u00a0=\u00a00.057, SRMR\u00a0=\u00a00.022 for BASDAI), demonstrating structural validity.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>This study supports the use of both ASDAS\u2010CRP and BASDAI in measuring disease activity in patients with axSpA in Singapore.<\/jats:p><\/jats:sec>","DOI":"10.1111\/1756-185x.13735","type":"journal-article","created":{"date-parts":[[2019,11,13]],"date-time":"2019-11-13T10:35:51Z","timestamp":1573641351000},"page":"2206-2212","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":32,"title":["Validity and reliability of the Ankylosing Spondylitis Disease Activity Score with C\u2010reactive protein (ASDAS\u2010CRP) and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) in patients with axial spondyloarthritis (axSpA) in Singapore"],"prefix":"10.1111","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7802-9696","authenticated-orcid":false,"given":"Yu Heng","family":"Kwan","sequence":"first","affiliation":[{"name":"Program in Health Services and Systems Research Duke\u2010NUS Medical School Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jun Jie","family":"Tan","sequence":"additional","affiliation":[{"name":"Department of Pharmacy Singapore General Hospital Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jie Kie","family":"Phang","sequence":"additional","affiliation":[{"name":"Department of Rheumatology and Immunology Singapore General Hospital Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1891-1892","authenticated-orcid":false,"given":"Warren","family":"Fong","sequence":"additional","affiliation":[{"name":"Department of Rheumatology and Immunology Singapore General Hospital Singapore Singapore"},{"name":"Department of Medicine Yong Loo Lin School of Medicine National University of Singapore Singapore Singapore"},{"name":"Duke\u2010NUS Medical School Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ka Keat","family":"Lim","sequence":"additional","affiliation":[{"name":"Program in Health Services and Systems Research Duke\u2010NUS Medical School Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hwee Ling","family":"Koh","sequence":"additional","affiliation":[{"name":"Department of Pharmacy Faculty of Science National University of Singapore Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nai Lee","family":"Lui","sequence":"additional","affiliation":[{"name":"Department of Rheumatology and Immunology Singapore General Hospital Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chuen Seng","family":"Tan","sequence":"additional","affiliation":[{"name":"Saw Swee Hock School of Public Health National University of Singapore Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Truls","family":"\u00d8stbye","sequence":"additional","affiliation":[{"name":"Program in Health Services and Systems Research Duke\u2010NUS Medical School Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6712-5535","authenticated-orcid":false,"given":"Julian","family":"Thumboo","sequence":"additional","affiliation":[{"name":"Program in Health Services and Systems Research Duke\u2010NUS Medical School Singapore Singapore"},{"name":"Department of Rheumatology and Immunology Singapore General Hospital Singapore Singapore"},{"name":"Department of Medicine Yong Loo Lin School of Medicine National University of Singapore Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ying Ying","family":"Leung","sequence":"additional","affiliation":[{"name":"Department of Rheumatology and Immunology Singapore General Hospital Singapore Singapore"},{"name":"Department of Medicine Yong Loo Lin School of Medicine National University of Singapore Singapore Singapore"},{"name":"Duke\u2010NUS Medical School Singapore Singapore"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2019,11,13]]},"reference":[{"key":"e_1_2_8_2_1","doi-asserted-by":"publisher","DOI":"10.1186\/s12891-017-1715-x"},{"key":"e_1_2_8_3_1","doi-asserted-by":"publisher","DOI":"10.1136\/annrheumdis-2016-210770"},{"key":"e_1_2_8_4_1","doi-asserted-by":"publisher","DOI":"10.1007\/s11136-018-1900-x"},{"key":"e_1_2_8_5_1","doi-asserted-by":"publisher","DOI":"10.1080\/1744666X.2018.1429918"},{"key":"e_1_2_8_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.semarthrit.2017.04.002"},{"key":"e_1_2_8_7_1","doi-asserted-by":"publisher","DOI":"10.1136\/ard.2008.100826"},{"issue":"2","key":"e_1_2_8_8_1","first-page":"146","article-title":"Validation of disease activity and functional status instruments in spondyloarthritis","volume":"33","author":"Quinzanos I","year":"2015","journal-title":"Clin Exp Rheumatol"},{"key":"e_1_2_8_9_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1756-185X.2010.01537.x"},{"key":"e_1_2_8_10_1","doi-asserted-by":"publisher","DOI":"10.1111\/1756-185X.12707"},{"key":"e_1_2_8_11_1","doi-asserted-by":"publisher","DOI":"10.1136\/annrheumdis-2012-202976"},{"key":"e_1_2_8_12_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10067-014-2729-5"},{"key":"e_1_2_8_13_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.semarthrit.2018.02.016"},{"key":"e_1_2_8_14_1","doi-asserted-by":"publisher","DOI":"10.1111\/1467-9566.12154"},{"issue":"12","key":"e_1_2_8_15_1","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 S","year":"1994","journal-title":"J Rheumatol"},{"key":"e_1_2_8_16_1","doi-asserted-by":"publisher","DOI":"10.1136\/ard.2009.108233"},{"key":"e_1_2_8_17_1","doi-asserted-by":"publisher","DOI":"10.1515\/sjpain-2018-0012"},{"issue":"3","key":"e_1_2_8_18_1","first-page":"358","article-title":"Metabolites of C\u2010reactive protein and vimentin are associated with disease activity of axial spondyloarthritis","volume":"37","author":"Siebuhr AS","year":"2019","journal-title":"Clin Exp Rheumatol"},{"key":"e_1_2_8_19_1","doi-asserted-by":"publisher","DOI":"10.1002\/art.38921"},{"key":"e_1_2_8_20_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00296-016-3567-3"},{"key":"e_1_2_8_21_1","doi-asserted-by":"publisher","DOI":"10.1007\/s11136-011-9960-1"},{"key":"e_1_2_8_22_1","doi-asserted-by":"publisher","DOI":"10.1093\/rheumatology\/ket396"},{"key":"e_1_2_8_23_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10067-018-4112-4"},{"key":"e_1_2_8_24_1","doi-asserted-by":"publisher","DOI":"10.1002\/art.21325"},{"key":"e_1_2_8_25_1","doi-asserted-by":"publisher","DOI":"10.1080\/10705519909540118"},{"key":"e_1_2_8_26_1","doi-asserted-by":"publisher","DOI":"10.1136\/rmdopen-2016-000319"},{"issue":"4","key":"e_1_2_8_27_1","first-page":"381","article-title":"Reliability and validity of the Thai version of bath ankylosing spondylitis indices","volume":"97","author":"Kittiyanpanya C","year":"2014","journal-title":"J Med Assoc Thai"},{"key":"e_1_2_8_28_1","doi-asserted-by":"publisher","DOI":"10.1007\/s10067-007-0573-6"},{"key":"e_1_2_8_29_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00296-017-3814-2"},{"key":"e_1_2_8_30_1","doi-asserted-by":"publisher","DOI":"10.1586\/1744666X.2015.1052795"},{"key":"e_1_2_8_31_1","doi-asserted-by":"publisher","DOI":"10.1111\/1756-185X.13299"}],"container-title":["International Journal of Rheumatic Diseases"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/1756-185X.13735","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1111\/1756-185X.13735","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/1756-185X.13735","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,9,8]],"date-time":"2023-09-08T22:51:40Z","timestamp":1694213500000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/1756-185X.13735"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,11,13]]},"references-count":30,"journal-issue":{"issue":"12","published-print":{"date-parts":[[2019,12]]}},"alternative-id":["10.1111\/1756-185X.13735"],"URL":"https:\/\/doi.org\/10.1111\/1756-185x.13735","archive":["Portico"],"relation":{},"ISSN":["1756-1841","1756-185X"],"issn-type":[{"value":"1756-1841","type":"print"},{"value":"1756-185X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,11,13]]},"assertion":[{"value":"2019-07-23","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2019-10-04","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2019-11-13","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}