Measurement properties of the Wheelchair Skills Test – Questionnaire for powered wheelchair users^*

Abstract

Purpose: To evaluate the test–retest reliability, concurrent validity and responsiveness of the Wheelchair Skills Test – Questionnaire (WST-Q) Version 4.1 for powered wheelchair users. Methods: A volunteer sample of 72 community-dwelling, experienced powered wheelchair users, ranging in age from 50 to 77 years, participated in this study. Participants completed measures at baseline and 1 month later. Results: Mean ± standard deviation total percentage WST-Q scores at baseline and 1 month were 83.7% ± 10.9 and 86.3% ± 10.0 respectively. Cronbach’s alpha was 0.90 and the 1 month test–retest intraclass correlation coefficient (ICC_1,1) was 0.78 (confidence interval: 0.68–0.86). There were no floor or ceiling effects. Percentages of agreement between baseline and 1 month for individual skills ranged from 72.2% to 100%. The correlations between the WST-Q and the objective Wheelchair Skills Test (WST), WheelCon and Life Space Assessment were r = 0.65, r = 0.47 and r = 0.47 respectively. The standard error of measurement (SEM) and smallest real difference (SRD) were 5.0 and 6.2 respectively. Conclusion: The WST-Q 4.1 has high internal consistency, strong test–retest reliability and strong support for concurrent validity and responsiveness.

Implications for Rehabilitation:

• There is evidence of reliability, validity and responsiveness of the Wheelchair Skills Test – Questionnaire (WST-Q) among experienced older adult powered wheelchair users.

• The WST-Q can be used to measure powered wheelchair skills, guide intervention and measure change over time.

• Outcome assessment (health care)
• rehabilitation
• wheelchairs

Acknowledgements

We thank Elmira Chan, MEd, Sarah McCuaig, BA, Jennifer Querques, BPh, Laura Titus, PhD, Fabrizio Farronato, BA, Elise Busilacchi, MSc, Valerie Lemay, MSc, Marie-Pierre Johnson, BSc, Deborah Stewart, PT/OT Asst. Dip and Lori Kennedy, BSc(Kin) for their assistance with data collection.

Declaration of interest

This study was funded by the Canadian Institutes of Health Research CanWheel team in Wheeled Mobility for Older Adults grant (AMG-100925). Salary/scholarship funds were provided by: the Canadian Institutes of Health Research (PWR) and the Fonds de recherche du Québec – Santé (FRQS) (FR).

We certify that no party having a direct interest in the results of the research supporting this article has or will confer a benefit on us or on any organization with which we are associated and we certify that all financial and material support for this research are clearly identified in the title page of the manuscript. The authors declare that they have no competing interests.

Notes

* Presented in part at: Annual Meeting of RESNA, Baltimore, June 28–July 3, 2012, Baltimore, MD, USA.