Table 2.

Study characteristics (n=5).

Author (year of publication)	Study design	Size, N	Population demographics	Study objective	Usability testing method	Usability outcome	Findings
Benham et al (2019) [59]	Observational (mixed methods exploratory)	12	92% White 67% female Mean age 70.2 (SD 3.6) yearsa	Examine applicability and effectiveness of a VRb intervention for pain, depression, and quality of life in older adults.	Qualitative interviews	Qualitative themes: usability assessment and satisfaction	All participants reported overall positive experiences. Overall, 47% experienced an undesirable symptom, but all symptoms were related to a specific activity that could be avoided in future use; 91.7% reported they would continue use if given the chance; and 100% would recommend the device to other seniors.
Fowler et al (2019) [58]	Observational (single-arm feasibility)	16	50% White, 25% African American or Black, 12% Hispanic or Latino, and 13% othera Mean age 48.88 (11.62) years 81% male	Assess effect and feasibility of VR usage on fear of movement, pain outcomes, and patient functioning.	Quantitative questionnaire	Ratings of immersion, self-reported VR intensity, session length, and side effects	Selected applications did not calibrate in intensity as expected (low-movement applications rated higher in intensity and high-movement applications rated lower). Sessions were also rated too short. Minor adverse events included cybersickness symptoms and neck strain.
Garcia-Palacios et al (2015) [61]	Randomized control trial	61	100% White 100% female Mean age 50.48 (SD 9.78) years 21% less than elementary level of education, 36% elementary level of education, 31% completed high school, and 11% completed universitya 79% married, 10% single, 10% divorced, and 2% widow	Assess acceptability and efficacy of VR based on activity level, pain, quality of life, and mood of patients with fibromyalgia.	Quantitative questionnaire	Rating of acceptability and satisfaction	Participants had high satisfaction with VR treatment. They found the treatment logical and useful and would definitely recommend it to a friend. The participants did not find the treatment aversive or unpleasant. The VR device was deemed highly useful.
Hennessy et al (2020) [60]	Observational (content validity and feasibility)	12	100% Blacka 67% female Mean age 54.3 (SD 5.1) years	Determine content validity and feasibility of VR application use.	Usability questionnaire (SUSc)	Ratings of content validity; SUS	All participants assigned higher avoidance, expected pain, and expected concern for high-intensity modules compared with low-intensity modules. Participants rated the usability of the VR application as acceptable.
Stamm et al (2020) [62]	Observational (usability evaluation)	15	Mean age 75.9 (SD 6.9) yearsa	Understand expectations, desires, preferences, and barriers of VR pain therapy. Determine frameworks of therapy by physiotherapists and psychotherapists.	Qualitative questionnaire	Expert and user requirements assessments	Key requirements were target-group–specific and included individual briefing, user-friendly handling, inclusion of movement limitations, presentation of everyday scenarios in combination with biofeedback, age-appropriate feedback through praise and awards, and a maximum exercise duration of 30 and 15 min of relaxation.

^aReported study demographic that met inclusion criteria.

^bVR: virtual reality.

^cSUS: System Usability Scale.