Table 2.

Engagement strategies used in the interventions.

Study	Providing health-related educational information	Reminding or alerting users	Motivational messages or encouragement	Recording and tracking health information	Providing guidance based on information entered by the user	Enabling 2-way communication with clinicians	Providing support through social networks	Supporting behavior change through rewards
Bengtsson et al [31]	No	Yes	Yes	Yes	No	No	No	No
Chandler et al [38]	No	Yes	Yes	Yes	Yes	No	No	No
Ciemins et al [49]	Yes	Unknown	No	Yes	Yes	No	No	No
Davidson et al [39]	No	Yes	Yes	No	No	No	No	No
Duan et al [43]	Yes	Yes	No	Yes	Yes	No	Yes (leaderboard module, version 4)	No
Gong et al [44]	No	Yes	No	Yes	Yes	Yes	No	No
Hallberg et al [32]	No	Yes	Yes	Yes	No	No	No	No
Kang and Park [25]	Yes	Yes	No	Yes	Yes	No	No	No
Kaplan et al [48]	Yes	Yes	Yes	Yes	Yes	No	No	Yes
Mao et al [26]	Yes	Yes	Yes	Yes	Yes	Yes	No	No
Márquez Contreras [45]	No	Yes	No	Yes	No	No	No	No
McGillicuddy et al [28]	No	Yes	No	Yes	Yes	No	No	No
Moore et al [37]	No	No	No	Yes	No	Yes	No	No
Morawski et al [27]	No	Yes	No	Yes	No	No	Yes	No
Ovbiagele et al [47]	No	Yes	Yes	Yes	Yes	No	No	No
Patel et al [51]	Yes	Yes	No	Yes	No	No	No	No
Persell et al [36]	Yes	Yes	Yes	Yes	Yes	Artificial intelligence coaching	No	No
Petrella et al [46]	No	No	No	Yes	Yes	No	No	No
Thies et al [14]	No	No	No	Yes	Yes	Yes	No	No
Toro-Ramos et al [50]	Yes	Yes	Yes	Yes	Yes	Yes	No	No
Weerahandi et al [52]	Yes	No	No	Yes	Yes	Yes	No	No