Reliability of a Spinal Cord Injury-Specific Extension of the Work Rehabilitation Questionnaire (WORQ-SCI)

The Work Rehabilitation Questionnaire (WORQ), an International Classification of Functioning, Disability, and Health (ICF)-based questionnaire, was developed to assess work-related functioning of persons with a range of health conditions. The WORQ has shown limitations in its applicability to persons with spinal cord injury (SCI). The purpose of this study was to investigate internal consistency, test-retest reliability, and agreement of the WORQ-SCI, a newly developed extension to the WORQ for use in persons with SCI.

A cross-sectional and test-retest reliability study was performed in eight Dutch rehabilitation centers specialized in SCI rehabilitation. Persons with SCI with first inpatient rehabilitation between 2015 and 2022 and work participation as a goal, completed the WORQ-SCI twice. Internal consistency (Cronbach's alpha), test-retest reliability (intra-class correlation, ICC), and agreement between measurement points (Bland-Altman plot) were analyzed.

A total of 175 participants completed the WORQ-SCI questionnaire at baseline (T1), of whom 59 completed the WORQ-SCI questionnaire a second time, with 52 reporting no changes in health or work status. Internal consistency for the WORQ-SCI was: 0.93 (23 items, N = 175). Test-retest reliability for the subgroup with no changes was ICC = 0.91 (95%-CI 0.84-0.95, N = 52). Bland-Altman plot for agreement between WORQ-SCI T1 and T2 (retest) suggested no systematic bias, with a mean difference of - 1.5 (SD 15.2) and 95% limits of agreement: ± 29.7.

The WORQ-SCI showed good internal consistency and test-retest reliability. The test-retest results provide insight into measurement error, emphasizing the robustness of the instrument over time. The WORQ-SCI could be used reliably to assess work-related functioning in persons with SCI, although limits of agreement suggest caution when interpreting change at the level of the individual.