Evidence map›Paper›PMID 42444531›Full record

ArticleInternational journal of rheumatic diseases2026

Psychometric Properties of the Work Ability Index Among Patients With Arthritis in Singapore.

Ling Xiang, Andrea Low, Ying-Ying Leung, Warren Fong, York-Kiat Tan, Wee-Hoe Gan, Nicholas Graves, Mihir Gandhi, Sungwon Yoon, Julian Thumboo

Abstract readValidation Study
In one paragraph

Article in International journal of rheumatic diseases, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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4 · The record

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5 · Who and what money

Authors and funding

10 authors.

Ling XiangDepartment of Rheumatology and Immunology, Singapore General Hospital, Singapore, Singapore.ORCID https://orcid.org/0000-0002-2883-6614
Andrea LowDepartment of Rheumatology and Immunology, Singapore General Hospital, Singapore, Singapore.
Ying-Ying LeungDepartment of Rheumatology and Immunology, Singapore General Hospital, Singapore, Singapore.
Warren FongDepartment of Rheumatology and Immunology, Singapore General Hospital, Singapore, Singapore.
York-Kiat TanDepartment of Rheumatology and Immunology, Singapore General Hospital, Singapore, Singapore.ORCID https://orcid.org/0000-0002-6944-8220
Wee-Hoe GanDepartment of Occupational and Environmental Medicine, Singapore General Hospital, Singapore, Singapore.
Nicholas GravesDivision of Innovation & Transformation, Singapore Health Services, Singapore, Singapore.ORCID https://orcid.org/0000-0002-5559-3267
Mihir GandhiBiostatistics, Singapore Clinical Research Institute, Singapore, Singapore.
Sungwon YoonCentre for Population Health Research and Implementation, Singapore Health Services, Singapore, Singapore.
Julian ThumbooDepartment of Rheumatology and Immunology, Singapore General Hospital, Singapore, Singapore.

Funding

Singapore Ministry of Health National Medical Research Council Health Services Research HSRGHP20nov-0001Singapore Ministry of Health National Medical Research Council Health Services Research NMRC/HSRG/0075/2017
6 · The paper itself

Abstract

aimThe Work Ability Index (WAI) is recommended for use among individuals with arthritis but has yet to be validated in Singapore. We therefore aimed to evaluate the psychometric properties of WAI among individuals with arthritis in Singapore and whether its first item (WAS) and a version without disease-related item (WAInodis) could be proxies for WAI.

methodsFactor structure, internal consistency, convergent validity, and known-groups validity of WAI were evaluated. Concurrent, convergent, and known-groups validity of WAS and WAInodis were examined to assess their potential as proxies.

resultsA total of 509 patients with arthritis and 499 healthy volunteers were included. A one-factor structure was identified for WAI. Internal consistency was acceptable (Cronbach's alpha = 0.725). Convergent validity was demonstrated by correlation with conceptually related measures including work productivity (rho = 0.586), coping (rho = 0.457), general health (rho = 0.497), and fatigue (rho = 0.527). Known-groups validity was demonstrated by significant difference in WAI score between participants with and without arthritis (37.6 vs. 42.1, p < 0.001). Compared to WAS, WAInodis exhibited stronger potential as a proxy, with stronger correlation with WAI (rho = 0.961 vs. 0.763), smaller difference from WAI (mean = -1.0 vs. 49.5), and stronger correlations with conceptually related measures.

conclusionWAI demonstrated relatively good psychometric properties among individuals with arthritis, adding to the literature supporting its role in assessing work ability, although further evaluation is needed. WAInodis may serve as a proxy for WAI in studies where the disclosure of medical conditions is a concern.

Indexed as

ArthritisDisability EvaluationPsychometricsWork Capacity EvaluationAdaptation, PsychologicalAdultAgedCase-Control StudiesCross-Sectional StudiesEfficiencyFemaleHealth StatusHumansMaleMiddle AgedPredictive Value of Testsosteoarthritispsoriatic arthritisrheumatoid arthritisspondyloarthritiswork ability index

Identifiers

PMID42444531
PMCPMC13366459

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