Table 3.
Overview of randomized controlled trials (n=6).
| Study | Participants, n (% female) | Age in years, mean (SD) | Intervention (duration) | Engagement strategy in intervention design by group | Recommended engagement strategy (author conclusion based on the usability of study arms) |
| Lappalainen et al, 2013 [15] | 24 (0) | 47 (7) | A total of 3 group meetings and personal use of web portal, apps, and devices (3 months) | CGa: No intervention; IGb: Personalized feedback | IG: Personalized feedback |
| Morris et al, 2015 [17] | 166 (72) | 24 (5) | Peer-to-peer platform for cognitive reappraisal and socioaffective support and supportive reappraisals from web-based crowd helpers (3 weeks) | CG: Expressive writing, web based; IG: 1. Short content; 2. Positive support messages from peers; 3. Quick feedback any time; 4. Repeated reminders; 5. Accessibility any time | IG: 1. Personalized feedback; 2. Support messages from peers; 3. Flexibility in use |
| Ly et al, 2017 [23] | 28 (54) | 26 (7) | Learn strategies of positive psychology through fully automated conversation, daily check-ins, and weekly summaries (2 weeks) | CG: No intervention; IG: Fully automated chatbot (conversational agent) | IG: Fully automated chatbot |
| Birk and Mandryk, 2019 [27] | 259 (51) | 35 (11) | Customization of avatar, ABMTc, and negative mood induction (3 weeks) | IG1: Customized avatar and ABMT; IG2: Customized avatar and no ABMT; IG3: Generic avatar and ABMT; IG4: Generic avatar and no ABMT | IG1: Avatar customization and personalization |
| Przybylko et al, 2019 [29] | 426 (69) | 47 (16) | Video presenting evidence-based strategies for promoting mental health and emotional wellness, daily and weekly challenges, gamification, and social forum (12 weeks) | CG: No intervention; IG: 1. Real-time coping strategies for daily mission; 2. Social forum with interactive component; 3. Rewards for completing missions; 4. Mission history available; 5. Push notifications alert for incomplete mission; 6. Bright graphics | IG: Interactive components in the social forum |
| Renfrew et al, 2020 [30] | 458 (78) | 46 (1) | Videos, workbook, reading materials related to the topic, and daily and weekly challenges (10 weeks) | CG: Automated email support; IG1: Automated email support and reminder SMS text messaging; IG2: Automated email support and videoconference session per week and 1 reminder SMS text message for videoconference per week | None (Videoconference mode had no effect on intervention engagement, and getting the chosen support style did not result in better engagement or outcomes) |
aCG: control group.
bIG: intervention group.
cABMT: attention bias modification training.