Test-Retest Reliability and Agreement of the Work Ability Index-Single Item in Persons With Physical Disabilities
Renée van Dinter1, Annemarie C Jenks1, Ellen H Roels1
1Center for Rehabilitation, Department of Rehabilitation Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Objective:
To assess the test-retest reliability and agreement of the work ability index-single item (WAS) in persons with a physical disability.
Design:
Test-retest study, with a 2-4 week interval. Test-retest reliability was computed using the intraclass correlation coefficient (ICC). The agreement was analyzed using Bland-Altman plots.
Setting:
Vocational rehabilitation department of a rehabilitation center.
Participants:
Patients with a physical disability (spinal cord injury, acquired brain injury, neuromuscular disease, or other).
Interventions:
Not applicable.
Main Outcome Measures:
The WAS consists of 1 question on self-reported current work ability compared with their highest work ability ever, rated on a 0-10 scale.
Results:
Data from 44 patients were available and 22 patients reported no changes in work or medical situation between the 2 measurements. After excluding 1 outlier in this subgroup (n=21), the ICC was 0.89 (95% confidence interval, 0.76-0.96), the mean test-retest difference was -0.05 points and the limits of agreement were ±2.4 points.
Conclusions:
The WAS is reliable for measuring work ability in persons with a physical disability. Using the WAS could be valuable as a routine outcome measure in vocational rehabilitation for persons with a physical disability.
Related Concept Videos
01:29Reliability and Validity
01:22Self-Report Tests of Personality
01:29Measures of Intelligence
Validity refers to how well a test measures what it claims to measure. An intelligence test should accurately assess intelligence rather than another characteristic, like anxiety. Criterion validity is one way to evaluate this;...