Table 3.
Subgroup analyses for overall attrition rate in conversational agent (CA)–delivered mental health interventions.
| Subgroups | Short-term studies (≤8 wk) | Long-term studies (>8 wk) | ||||||||||||||||||
|
|
Interventions, n | Attrition rate, % (95% CI) | I2 (%) | P value | Interventions, n | Attrition rate, % (95% CI) | I2 (%) | P value | ||||||||||||
| Risk of bias | .21 |
|
.22 | |||||||||||||||||
|
|
High risk of bias | 8 | 26.18 (15.69-38.13) | 89.6 |
|
4 | 22.31 (17.85-27.10) | 0 |
|
|||||||||||
|
|
Low risk of bias | 18 | 14.76 (4.27-29.25) | 95.6 |
|
11 | 28.35 (20.25-37.20) | 95.4 |
|
|||||||||||
| Funding source | .71 |
|
.38 | |||||||||||||||||
|
|
Industry funding | 9 | 20.43 (8.78-35.06) | 92.4 |
|
4 | 32.36 (18.14-48.46) | 97.0 |
|
|||||||||||
|
|
Public funding only | 17 | 16.56 (6.35-29.79) | 95.1 |
|
11 | 23.19 (15.92-33.65) | 92.1 |
|
|||||||||||
| Duration (wk) | .43 |
|
.68 | |||||||||||||||||
|
|
0-4 | 17 | 15.57 (5.10-29.92) | 95.3 |
|
N/Aa | N/A | N/A |
|
|||||||||||
|
|
5-8 | 9 | 23.15 (11.13-37.67) | 93.4 |
|
N/A | N/A | N/A |
|
|||||||||||
|
|
9-12 | N/A | N/A | N/A |
|
11 | 25.30 (19.35-31.75) | 90.3 |
|
|||||||||||
|
|
>13 | N/A | N/A | N/A |
|
4 | 30.04 (10.75-53.88) | 96.1 |
|
|||||||||||
| Study design | .65 |
|
.19 | |||||||||||||||||
|
|
RCTb | 19 | 19.68 (10.34-30.95) | 95.2 |
|
14 | 26.00 (19.33-33.27) | 94.3 |
|
|||||||||||
|
|
Pilot RCT | 7 | 12.73 (0-38.45) | 91.8 | 1 | N/A | N/A | |||||||||||||
| Type of disorder | .80 |
|
.32 | |||||||||||||||||
|
|
Depression | 6 | 17.89 (5.44-34.60) | 91.5 |
|
11 | 24.03 (17.74-30.93) | 91.4 |
|
|||||||||||
|
|
Depression and anxiety | 5 | 7.68 (0-40.93) | 97.1 |
|
N/A | N/A | N/A |
|
|||||||||||
|
|
Mental well-being | 9 | 24.29 (8.37-44.57) | 94.2 |
|
N/A | N/A | N/A |
|
|||||||||||
|
|
Otherc | 4 | 20.02 (10.61-31.36) | 81.9 |
|
3 | 33.77 (17.01- 52.90) | 94.9 |
|
|||||||||||
| With CBTd | .41 |
|
.65 | |||||||||||||||||
|
|
Yes | 17 | 21.35 (11.26-33.41) | 95.1 |
|
12 | 27.51 (20.16-35.31) | 94.5 | ||||||||||||
|
|
No | 9 | 11.64 (0.21-33.29) | 93.8 |
|
3 | 22.99 (7.94-42.72) | 92 | ||||||||||||
| With mindfulness component | .02 |
|
.27 | |||||||||||||||||
|
|
Yes | 12 | 30.24 (17.02-45.27) | 95.5 |
|
11 | 23.89 (17.67-30.71) | 91.5 |
|
|||||||||||
|
|
No | 14 | 8.66 (0.89-21.20) | 92.8 |
|
4 | 34.35 (18.00-52.84) | 93.8 |
|
|||||||||||
| Personalization | .63 |
|
.53 | |||||||||||||||||
|
|
No personalization | 6 | 17.04 (5.08-33.33) | 84.7 |
|
2 | 38.10 (10.38-70.94) | 97.1 |
|
|||||||||||
|
|
Minimal personalization | 2 | 44.57 (2.50-92.50) | 96.0 |
|
N/A | N/A | N/A |
|
|||||||||||
|
|
Substantial personalization | 9 | 21.56 (12.52-32.12) | 89.0 |
|
12 | 25.25 (19.16-31.85) | 91.3 |
|
|||||||||||
|
|
Major personalization | 9 | 10.98 (0-35.05) | 96.5 |
|
1 | 19.51 (8.61-33.23) | N/A |
|
|||||||||||
| CA algorithm | .42 |
|
.49 | |||||||||||||||||
|
|
Rule based | 16 | 21.53 (11.72-33.12) | 93.1 |
|
13 | 25.02 (19.30-31.19) | 90.6 |
|
|||||||||||
|
|
AIe enhanced | 10 | 13.25 (1.29-32.79) | 96.2 |
|
2 | 37.16 (8.05-72.63) | 95 |
|
|||||||||||
| Type of CA | .14 |
|
.16 | |||||||||||||||||
|
|
No avatar | 3 | 33.36 (15.39-54.24) | 94.36 |
|
12 | 29.21 (21.81-37.19) | 94.6 |
|
|||||||||||
|
|
ECAf | 6 | 8.03 (1.37-18.04) | 59 |
|
2 | 15.35 (5.05-29.63) | 80.3 |
|
|||||||||||
|
|
Avatar | 13 | 20.13 (6.67-37.97) | 96.4 |
|
1 | 19.51 (8.61-33.23) | N/A |
|
|||||||||||
|
|
Not specified | 4 | 15.15 (1.79-35.93) | 86.4 |
|
N/A | N/A | N/A |
|
|||||||||||
| With rewards component | .74 |
|
<.001g | |||||||||||||||||
|
|
Yes | 15 | 16.63 (9.93-27.41) | 92.4 |
|
1 | 54.83 (49.60-60.00) | 89.9 |
|
|||||||||||
|
|
No | 11 | 20.07 (5.77;-39.39) | 96 |
|
14 | 24.68 (19.20-30.59) |
|
|
|||||||||||
| Reminder | .20 |
|
.98 | |||||||||||||||||
|
|
With reminder | 14 | 23.96 (12.19-37.99) | 94.8 |
|
7 | 26.42 (14.80-39.96) | 95.7 |
|
|||||||||||
|
|
Without reminder | 12 | 11.43 (1.76-26.27) | 94.7 |
|
8 | 26.51 (17.85-36.16) | 92.1 |
|
|||||||||||
| Delivery channel | .02g |
|
<.001g | |||||||||||||||||
|
|
Web based | 4 | 30.74 (15.26-48.70) | 91.5 |
|
11 | 26.96 (20.73-33.66) | 90.8 |
|
|||||||||||
|
|
Computer- or laptop computer– or tablet computer–embedded program | 6 | 4.72 (0.06-13.49) | 61.5 |
|
1 | 9.33 (3.62-17.12) | N/A |
|
|||||||||||
|
|
Smartphone app | 10 | 14.32 (5.71-25.56) | 87.5 |
|
1 | 54.83 (49.60-60.00) | N/A |
|
|||||||||||
|
|
Messenging app based (meaning Slack, Facebook Messenger, or WeChat based) | 6 | 33.27 (10.58-60.80) | 96.9 |
|
1 | 19.51 (8.61-33.23) | N/A |
|
|||||||||||
|
|
Not specified | N/A | N/A | N/A |
|
1 | 22.11 (14.27-31.06) | N/A |
|
|||||||||||
| With blended component | .38 |
|
.02 | |||||||||||||||||
|
|
Yes | 3 | 19.12 (10.38-29.56) | 95.1 |
|
6 | 18.65 (12.86-25.20) | 75.4 |
|
|||||||||||
|
|
No | 23 | 9.89 (0.35-26.31) | 38.8 |
|
9 | 32.54 (23.01-42.84) | 94.9 |
|
|||||||||||
| Enrollment method | .15 |
|
.12 | |||||||||||||||||
|
|
Remote options only | 14 | 26.63 (15.19-39.82) | 95.4 |
|
9 | 30.18 (20.38-40.95) | 95.6 |
|
|||||||||||
|
|
With in-person option | 10 | 9.68 (0.15-27.14) | 92 |
|
6 | 21.28 (16.69-26.26) | 53.7 |
|
|||||||||||
|
|
Not specified | 2 | 5.02 (0-33.08) | 88 |
|
N/A | N/A | N/A |
|
|||||||||||
| Study population | .05g |
|
.41 | |||||||||||||||||
|
|
At risk | 11 | 19.92 (1.53-29.81) | 90.1 |
|
7 | 30.10 (17.09-44.93) | 96.4 |
|
|||||||||||
|
|
Clinical | 4 | 3.53 (0-13.05) | 36 |
|
8 | 23.87 (18.55-29.61) | 76.5 |
|
|||||||||||
|
|
General | 11 | 22.05 (6.73-42.30) | 96.1 |
|
N/A | N/A | N/A |
|
|||||||||||
| Session length | .61 |
|
.34 | |||||||||||||||||
|
|
Defined session length | 15 | 20.26 (9.93-32.79) | 94.1 |
|
14 | 27.05 (20.28-34.38) | 94.3 |
|
|||||||||||
|
|
User determined | 11 | 15.31 (3.17-33.12) | 95.4 |
|
1 | 19.51 (8.61-33.23) | N/A |
|
|||||||||||
| With symptom trackers component | .99 |
|
.003 | |||||||||||||||||
|
|
Yes | 14 | 17.77 (6.44-32.52) | 93.9 |
|
6 | 16.36 (10.32-23.39) | 64.1 |
|
|||||||||||
|
|
No | 12 | 18.22 (7.21-32.44) | 95.3 |
|
9 | 33.48 (24.91-42.62) | 95.4 |
|
|||||||||||
aN/A: not applicable.
bRCT: randomized controlled trial.
cAnxiety only, panic disorder, height phobia, gambling disorder, substance abuse, attention-deficit/hyperactivity disorder, irritable bowel syndrome, eating disorder, and personality disorder.
dCBT: cognitive behavioral therapy.
eAI: artificial intelligence.
fECA: embodied CA.
gSubgroup analyses were not significant after dropping subgroups with <5 studies.