Table 3 Range of user engagement metrics across digital mental health interventions

Rate of uptake

The number of participants that downloaded the intervention/created an account/commenced the intervention/activated the app/ used the app/logged on at least once

11

67.5% (n = 27/40)⁵⁵ to 99% (n = 127/128)⁵⁶

Time (min/h) spent on app

Mean time spent on app over trial (min)

6

41.14⁵⁷–530.4 min⁵⁸

Median time spent on app over trial (min)

2

26.8⁵⁹–318 min⁵⁸

Mean daily use (min)

2

10.8⁶⁰–15.25 min⁶¹

Median daily use (min)

1

13.93 min⁶¹

Mean hours spent on app per week (h)

1

3.10⁶²

Mean weekly use (min)

2

37.9⁶²–103 min⁶³

Days of active use

Mean number of days of active use overall

5

6.38⁵⁵–23.07 days⁵⁷

Median number of days of active use overall

1

17 days⁶¹

Logins

Percentage of users logged on at least once a day

3

94%⁶⁴–96%⁶⁵

Average percentage of logins daily

1

75%⁶⁶

Mean number of logins/visits over the intervention period

8

11.52⁴⁶–106.84 logins²⁶

Median logins to app overall

3

9.5⁶⁷–19 logins⁶⁸

Modules completed

Percentage of users that completed the first/introductory module

6

60.1%⁵⁶ – 95%^56,69

Percentage of users that completed the whole programme OR percentage of users that completed the programme per protocol

17

7/84 (8%)⁴²–25/25 (100%)⁴³

Mean percentage of modules completed

13

12.38/40 (30.95%)⁴⁴–6.84/7 (98%)⁴⁵

Median completion of modules

1

5 modules (5/8 = 63%)⁵⁸

Study metrics

Number of trial surveys completed

2

48%^70,71 - 68.7%⁷⁰

Number of participants still engaged at the completion of the study

2

8.1% at 18 months²⁶–26% at 12 weeks⁷²

Messages sent and received

Mean number of messages sent from user to coach/therapist/clinician

3

10.35⁴⁴–22⁷³

Mean number of messages sent from coach/therapist/clinician to user

3

25.08⁴⁴–54⁷³

Posts and comments made

Mean number of newsfeed posts and/or comments

1

21.49²⁶

Median number of newsfeed posts and/or comments

1

7²⁶

Participant self-report

User self-reported engagement

15

N/A

Miscellaneous

Non-comparable engagement metrics

11

N/A