Driving to Learn in a powered wheelchair: inter-rater reliability of a tool for assessment of joystick-use

People with profound cognitive disabilities are not expected to learn powered mobility use. The Driving to Learn project focussed on what this population could achieve from practising in a joystick-operated powered wheelchair. By means of using grounded theory methodology an eight-phase process 'growing consciousness of joystick-use' was identified. In addition, a tool for assessment of actual phase of joystick-use and facilitating strategies for each phase emerged. The aim of the present study was to evaluate inter-rater reliability of the assessment tool.

The first author (LN) selected 24 video-sequences within the video data collected in the project. Each of the eight phases in the identified process were represented by three video-clips. The video-clips ranged in length between two to five minutes. LN's ratings served as criterion rating against which three independent raters' judgements were compared. The three raters were all occupational therapists, and two were experienced with the Driving to Learn method, powered wheelchair provision and the target population; and one was inexperienced.

When comparing the three raters' assessments with that of LN (N = 72), the calculation gave a weighted kappa value of 0.85. All raters judged the tool as having a high degree of usability for assessing phases of joystick-use. Minimal differences were found between the experienced and inexperienced raters. CONCLUSION AND SIGNIFICANCE OF THE STUDY: The inter-rater reliability of the assessment tool was very good. The findings indicate that the tool is reliable and has clinical usability in occupational therapy practice.