Validation of the work-ability support scale in individuals seeking to return to work after severe acquired brain injury

Abstract

Purpose

To assess the reliability and validity of the work-ability support scale (WSS) in a severe traumatic/acquired brain injury (TBI/ABI) population seeking to return to work (RTW).

Materials and methods

One hundred forty-four clients were enrolled in a vocational rehabilitation (VR) intervention trial through the Brain Injury Rehabilitation Program in New South Wales, Australia. Each client’s primary brain injury clinician and VR provider completed the WSS pre- and post-intervention. Validating measures assessing dysexecutive behavior, disability, participation, and work instability were completed. Several aspects of reliability and validity were evaluated.

Results

Internal consistency was excellent for Part A (Cronbach’s αs > 0.9) but unacceptably low to questionable for Part B (αs < 0.6). Inter-rater reliability between clinicians and VR providers was generally fair to moderate for Part A (κ_w < 0.6) and worse for Part B (κ_w < 0.5), with both slightly improving at post-intervention. Strong support was found for predictive and convergent validity, but not divergent validity. Confirmatory factor analysis indicated a poor fit for Part A, whereas most Part B fit indices met criteria.

Conclusions

The WSS can play a useful role in assessing return to work (RTW) potential, planning and evaluation after severe TBI/ABI. Training could improve consistency of administration among staff working across health and VR service sectors.

IMPLICATIONS FOR REHABILITATION

• The work-ability support scale (WSS) has potential as a screening tool in assisting return to work (RTW) assessment, planning, and evaluation, following severe traumatic brain injury and acquired brain injury.

• Employment success following a RTW intervention was predicted by the initial WSS Part A total score.

• The low inter-rater reliability between brain injury clinicians in health settings and vocational rehabilitation providers suggests that training will be important to improve consistency in WSS administration across service sectors.

Keywords:

• Acquired brain injury
• psychometrics
• reliability
• return to work
• traumatic brain injury
• vocational rehabilitation
• validity
• work-ability support scale

Acknowledgments

The authors would like to thank the NSW BIRP clinicians and the VR providers who completed the WSS and validating measures for this study, all of the clients of the VIP1.0 trial, as well as research staff from the Brain Injury Rehabilitation Directorate, Agency for Clinical Innovation, who took primary responsibility for data collection.

Disclosure statement

The salary of author GS is supported in part by the NSW icare Lifetime Care and Support Scheme. The other authors declare no conflicts of interest.

Data availability statement

The data that support the findings of this study are available from the corresponding author (GS) upon reasonable request.

Australia and New Zealand Clinical Trials Registry ACTRN12622000769785.

Additional information

Funding

The VIP1.0 trial was sponsored by the NSW icare Lifetime Care and Support Scheme and the State Insurance Regulatory Authority. The sponsors were not involved in the design, analytic strategy, or interpretation of the results of this secondary analysis of the VIP1.0 trial dataset, nor the decision to submit the article for publication.