Interrater Reliability of the Power Mobility Road Test in the Virtual Reality–Based Simulator-2

• The Virtual Reality–based SIMulator–version 2 (VRSIM-2) was developed to provide a safe environment where new users could learn to improve their electric-powered wheelchair (EPW) driving skills, until they felt confident enough to attempt the maneuvers in the real world.
• The primary goal of VRSIM-2 was to be an effective EPW simulator that was useful in administering the Power Mobility Road Test (PMRT) within a virtual environment using 4 different human-machine interfaces (HMIs).
• These HMIs were intended to provide the necessary customization of VRSIM-2 to be used in different clinical settings.
• The current study tests the hypothesis that the PMRT administered through different interfaces of VRSIM-2 and the real world will have high interrater reliability (intraclass correlation coefficient >.75) between 2 raters.
• Overall, high interrater reliability was found between 2 raters while administering the PMRT using the different interfaces of the VRSIM-2, illustrating that if 2 clinicians administer the PMRT for the same user using VRSIM-2, VRSIM-2 will elicit a similar clinical rating from both the clinicians.

ObjectiveTo assess interrater reliability of the Power Mobility Road Test (PMRT) when administered through the Virtual Reality–based SIMulator–version 2 (VRSIM-2).DesignWithin-subjects repeated-measures design.SettingParticipants interacted with VRSIM-2 through 2 display options (desktop monitor vs immersive virtual reality screens) using 2 control interfaces (roller system vs conventional movement-sensing joystick), providing 4 different driving scenarios (driving conditions 1–4). Participants performed 3 virtual driving sessions for each of the 2 display screens and 1 session through a real-world driving course (driving condition 5). The virtual PMRT was conducted in a simulated indoor office space, and an equivalent course was charted in an open space for the real-world assessment. After every change in driving condition, participants completed a self-reported workload assessment questionnaire, the Task Load Index, developed by the National Aeronautics and Space Administration.ParticipantsA convenience sample of electric-powered wheelchair (EPW) athletes (N=21) recruited at the 31st National Veterans Wheelchair Games.InterventionsNot applicable.Main Outcome MeasuresTotal composite PMRT score.ResultsThe PMRT had high interrater reliability (intraclass correlation coefficient [ICC]>.75) between the 2 raters in all 5 driving conditions. Post hoc analyses revealed that the reliability analyses had >80% power to detect high ICCs in driving conditions 1 and 4.ConclusionsThe PMRT has high interrater reliability in conditions 1 and 4 and could be used to assess EPW driving performance virtually in VRSIM-2. However, further psychometric assessment is necessary to assess the feasibility of administering the PMRT using the different interfaces of VRSIM-2.