Table 2.

Summaries of usability, feasibility, acceptability, and efficacy by type of techniques in high-income countries (HICs) and low- and middle-income countries (LMICs).

Techniques and groups			Usability		Feasibility		Acceptability		Efficacy
Videoconferencing platforms
	HICs (n=11)	—a		Three studies reported a completion rate between 92% and 100%. Three studies reported qualitative feedback of highly perceived benefits. Three studies reported technology-related challenges.		Five studies reported high levels of overall satisfaction.		Nine studies reported psychotherapy improved depressive levels and 5 studies found improved anxiety symptoms. One study found no effects on decreasing anxiety symptoms.
	LMICs (n=5)	—		Two studies reported the mean attendance ranges from 6.4 (SD 2.8) to 10.26 (SD 7.02).		One study reported high levels of satisfaction.		Three studies reported improvements in depressive symptoms or negative effects. Two studies reported no effects on decreasing depression levels.
Web-based programs
	HICs (n=17)	Two studies reported a significant increase in registered users. One study reported a high rating in usability.		Five studies reported the completed rate ranged from 30.5% to 85%. Three studies reported retention rate, which ranged from 30.5% to 85%. One study reported high attrition rate of 13%. One study reported strong attendance. Two studies reported that retentions were strong. Two studies reported high ratings of feasibility, and one study reported technical difficulty.		Five studies reported high satisfaction. One study reported that acceptability scores were significantly better than average. Three studies reported high acceptability and rated the interventions as acceptable, helpful, appropriate, and positive.		Eight studies reported improvement in anxiety symptoms and anxiety-related social impairment neither with nor without controls. Two studies indicated no effects on reducing anxiety. Five studies indicated improvement in depression symptoms and depression severity. One study reported no difference in depressive symptoms when compared with onsite groups. Three studies reported improved stress-related symptoms. Two studies reported reductions in COVID-19–related worry. One study indicated improvements in insomnia.
	LMICs (n=4)	One study reported the mean time spent was 35.63 (SD 25.41) min.		One study reported a completion rate of 87.4%. One study reported high attendance and high retention rates (91.2%).		One study reported high ratings of acceptability and the other a high level of satisfaction.		Four studies indicated improvement in anxiety symptoms neither with no controls nor control groups. Two studies reported improvement in depressive symptoms with no controls. One study reported a reduction in stress and burnout.
Smartphone apps
	HICs (n=11)	Two studies reported high usability scores. Two studies reported user engagement. The time ranged from 36.7 min over 12 weeks to 1424 min over 14 weeks.		One study reported the number of days retained was 42.44 (SD 44.40). Three studies reported a retention rate that ranged from 28.3% to 85.7%.		Two studies rated the intervention as acceptable, and 2 studies rated the intervention as satisfied. One rated the intervention as good. One rated the intervention as helpful.		Four studies reported reduced depressive symptoms compared with the preintervention and waitlist groups. Five studies reported similar improvements in anxiety symptoms compared with the preintervention, waitlist group, and a control app with limited access to psychoeducational content.
	LMICs (n=3)	—		—		One study indicated high satisfaction and would recommend the service. One study reported helpful and enjoyable.		Two studies reported improvements in depressive symptoms, insomnia, psychological flexibility, and self-compassion, either with no controls or in comparison with the waitlist group.
Texting
	HICs (n=5)	One study reported high usability.		Two studies reported a completion rate of 16% and 78%, respectively.		One study reported a high level of overall satisfaction.		Four studies reported an improved mood rating was observed at posttreatment assessment either with or without the control group.
	LMICs (n=0)	—		—		—		—
Social media
	HICs (n=1)	—		One study reported high retention.		One study reported high acceptability.		One study reported an effect on psychological distress, quality of life, functioning, loneliness, and physical activity without a control group.
	LMICs (n=2)	One study reported an average user time of 18.7 hours.		—		—		Two studies reported improvements in anxiety and depressive symptoms when compared with either the usual care or the waitlist group.
Hotline and telephone calls
	HICs (n=2)	One study reported 5.73 (SD 3.22) calls/day.		One study reported a dropout rate of 7.5%.		—		One study reported improvements in loneliness, depression, anxiety, and general mental health.
	LMICs (n=1)	—		—		One study reported high satisfaction, and the participants would use again, and would recommend it to others.		—
Robotic telemedicine and VRb
	HICs (n=2)	One study reported an average of 78 (SD 24.8) times.		One reported a completion rate of 58%.		One study reported high satisfaction.		One study reported a decrease in anxiety symptoms and stress symptoms.
	LMICs (n=1)	One study reported an overall positive impression of the multimodal robotic system.		One study reported the need to adjust some features.		—		—

^aNo evidence found.

^bVR: virtual reality.