title: Validity and Reliability of the 8-Item Work Limitations Questionnaire.
abstract: Purpose To evaluate factorial validity, scale reliability, test-retest reliability, convergent validity, and discriminant validity of the 8-item Work Limitations Questionnaire (WLQ) among employees from a public university system. Methods A secondary analysis using de-identified data from employees who completed an annual Health Assessment between the years 2009-2015 tested research aims. Confirmatory factor analysis (CFA) (n = 10,165) tested the latent structure of the 8-item WLQ. Scale reliability was determined using a CFA-based approach while test-retest reliability was determined using the intraclass correlation coefficient. Convergent/discriminant validity was tested by evaluating relations between the 8-item WLQ with health/performance variables for convergent validity (health-related work performance, number of chronic conditions, and general health) and demographic variables for discriminant validity (gender and institution type). Results A 1-factor model with three correlated residuals demonstrated excellent model fit (CFI = 0.99, TLI = 0.99, RMSEA = 0.03, and SRMR = 0.01). The scale reliability was acceptable (0.69, 95% CI 0.68-0.70) and the test-retest reliability was very good (ICC = 0.78). Low-to-moderate associations were observed between the 8-item WLQ and the health/performance variables while weak associations were observed between the demographic variables. Conclusions The 8-item WLQ demonstrated sufficient reliability and validity among employees from a public university system. Results suggest the 8-item WLQ is a usable alternative for studies when the more comprehensive 25-item WLQ is not available.
authors.affiliation: Department of Health Promotion and Behavioral Sciences, School of Public Health, The University of Texas Health Science Center at Houston, 7000 Fannin Street, Houston, TX, 77030, USA. timothy.j.walker@uth.tmc.edu.
authors.forename: Timothy J
authors.identifier: http://orcid.org/0000-0003-3171-5431
authors.initials: TJ
authors.lastname: Walker
authors.affiliation: Department of Management, Policy and Community Health, School of Public Health, The University of Texas Health Science Center at Houston, 1200 Pressler Street, Houston, TX, 77030, USA.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Tullar
authors.affiliation: Department of Health Promotion and Behavioral Sciences, School of Public Health, The University of Texas Health Science Center at Houston, 7000 Fannin Street, Houston, TX, 77030, USA.
authors.forename: Pamela M
authors.initials: PM
authors.lastname: Diamond
authors.affiliation: Department of Epidemiology, Human Genetics and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Austin, TX, USA.|Department of Kinesiology and Health Education, The University of Texas at Austin, 1616 Guadalupe, Austin, TX, 78701, USA.
authors.forename: Harold W
authors.initials: HW
authors.lastname: Kohl
authors.affiliation: Department of Health Policy and Management, Robert Stempel College of Public Health and Social Work, Florida International University, AHC5 4534 11200 SW 8th Street, Miami, FL, 33199, USA.|Institute for Work and Health, Toronto, ON, Canada.
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Amick
mesh_terms: D000328:Adult; D002908:Chronic Disease / Q000453:epidemiology; D005163:Factor Analysis, Statistical; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D016272:Occupational Health / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D011795:Surveys and Questionnaires / Q000592:standards*; D014938:Work Capacity Evaluation; D000066477:Work Performance
keywords: Employee health; Presenteeism; Productivity; Work; Work performance