Table 4 Summary of outcome measures and results
No. | First author/published year/Country | Main outcome measures | Secondary outcome measures | |||||
|---|---|---|---|---|---|---|---|---|
Physical activity (PA) | Diet | Weight | Engagement | Acceptability and satisfaction | Adverse event | Other outcomes | ||
Results | Results | Results | Results | Results | Results | Results | ||
Randomized controlled trials | ||||||||
1 | Kramer J/a 2020/ Switzerland [31] | OM (Daily step count obtained from smartphone) | NR | NR | OM (Rate of individuals who stopped using the app) | NR | NR | NR |
Daily cash incentives increased step-goal achievement by 8.1% (CI: [2.1, 14.1]) and, only in the no-incentive control group, action planning increased step-goal achievement by 5.8% (CI: [1.2, 10.4]). | NR | NR | 30% of participants stopped using the app over the course of the study. | NR | NR | NR | ||
2 | Kunzler F/b 2019/ Switzerland [33] | OM (Daily step count obtained from smartphone) | NR | NR | OM (Just-in-time-response rate, overall response rate, conversation engagement, response delay obtained from the chatbot) | NR | NR | NR |
Physical activity goal completion rate was correlated with overall response rate (r = 0.53, p < 0.001), just-in-time response rate (r = 0.42, p < 0.001), conversation rate (r = 0.38, p < 0.001) and average response delay (r = − 0.27, p < 0.001). | NR | NR | Intrinsic factors: Device type, age, and personality traits had a significant effect on the just-in-time response rate, conversation rate, and total response rate. Extrinsic factors: Time and day of the delivery, phone battery, device interaction, and location had significant effects on just-in-time response, conversation engagement, and response delay. | NR | NR | NR | ||
3 | Piao M/ 2020/ South Korea [32] | SR (Self-Report Habit Index) | NR | NR | NR | NR | NR | NR |
After 4 weeks of intervention without providing the intrinsic rewards in the control group, the change in SRHI scores was 13.54 (SD ± 14.99) in the intervention group and 6.42 (SD ± 9.42) in the control group (p = .04). When all rewards were given to both groups, from the fifth to twelfth week, the change in SRHI scores of the intervention and control groups was comparable at 12.08 (SD ± 10.87) and 15.88 (SD ± 13.29), respectively (p = .21) The level of physical activity showed a significant difference between the groups after 12 weeks of intervention (p = .045) | NR | NR | NR | NR | NR | NR | ||
4 | Carfora V/ 2019/ Italy [34] | NR | SR (Self-reported RPMC; intention; attitude; regret on RPMC) | NR | NR | NR | NR | NR |
NR | The emotional condition had stronger anticipated regret and higher intention to reduce RPMC, as compared to the control condition (p = .01 and p = .02 respectively). Both emotional and informational groups showed lower self-reported RPMC as compared to control. (p = .03 and p = .05 respectively). | NR | NR | NR | NR | NR | ||
Non-randomized studies | ||||||||
5 | Maher CA/ 2020/ Australia [20] | SR (Active Australia Survey) | SR (14-item Australian Mediterranean Diet Adherence) | OM (Seca 703) | OM (Number of weekly check-in obtained from the chatbot) | NR | NR | OM (Feasibility of subject enrollment) |
Increased MVPA 109.8 (95% CI 1.9 to 217.7, p = .005) minutes per day from baseline to 12 weeks. | Increased 5.7 (95% CI 4.2 to 7.3, p < .001) points in diet adherence from baseline to 12 weeks. | Lost 1.3 (95% CI − 25 to − 0.7, p = .01) kg from baseline to 12 weeks. | Mean weekly chatbot interaction 6.9 times out of 11 possible interactions. | NR | No adverse events reported | Enrolled 31 out of 99 screened participants in the 6- week enrollment period | ||
6 | Fadhil A/2019/NR [35] | SR (Physical activity intention) | SR (Healthy diet intention) | NR | NR | SR (TAM questionnaire) | NR | SR (AttrakDiff questionnaire) |
Results showed no difference between the three weeks; the scores remained unchanged for the physical activity. | Results showed no difference between the three weeks; the scores remained unchanged for the healthy diet. | NR | NR | The scales “ease of use,” “attitude,” and “intention” towards using the system were significantly higher than the middle score (respectively: t(17) = 4.9, p < .01; t(17) = 2.5, p < .05; t(17) = 3.1, p < .01). | NR | Average scores were statistically higher than 4 for each dimension: pragmatic (t(17) = 5.41, p < .01), hedonic (t(17) = 3.4, p < .01), appealing (t(17) = 4.2, p < .01), and social (t(17) = 2.6, p < .05). | ||
7 | Stephens/2019/ U.S. [21] | SR (Target goal progress) | NR | NR | OM (Duration of conversation, Quantity of messages exchanged, Number of hours support exchanged, Percentage of exchanges outside of typical office hours obtained from the chatbot, Ratio of chatbot-initiated vs. patient-initiated conversations obtained from the chatbot) | SR (Helpfulness) | NR | NR |
Adolescent patients reported experiencing positive progress toward their goals 81% of the time. | NR | NR | A total of 4123 messages were exchanged between participants and Tess. The average duration of conversations between Tess and patients was approximately 12.5 min (SD = ± 15.62 min). The median length of conversations was nearly 6 min, Tess provided about 55 h and 45 min of support for the adolescent patients, 17.8% of which was provided outside of typical office hours. A majority of the conversations were Tess initiated (73.6%) compared to patient initiated. | Patients indicated that Tess was helpful 96% of the time. | NR | NR | ||
8 | Casas J/2018/ Switzerland [36] | NR | SR (Meal consumption) | NR | NR | SR (Chatbot Effectiveness) | NR | NR |
NR | Only 11% of participants succeeded with their goals. In 65% of the cases the person has improved his consumption. In 12% of cases, consumption remained stable and in the remaining 24%, their consumption has worsened. | NR | NR | 82% of participants said that Rupert allowed them to think and be aware of their consumption. 86% reported answering honestly to the daily requests of the chatbot. 70% thought the chatbot intervention was efficient. | NR | NR | ||
9 | Kocielnik R/ 2018/ U.S. [37] | SR (Habituation Action; Understanding; Reflection; Critical reflection adapted from Kember et al. 2000) OM (Step count obtained from fitness trackers) SR (Physical activity awareness) | NR | NR | OM (Participant interactions with the system: 1) number of dialogues responded to, 2) the time until a response was made, 3) the length and content of responses obtained from the chatbot) SR (Willingness to use the system for additional 2 weeks without compensation) | NR | NR | SR (Mindfulness) |
Significant difference in Habitual Action (HA) for pre (M = 3.16, SD = 1.06) to post (M = 3.53, SD = 0.89) study measurements; t(32) = −2.04, p < 0.05. A weakly significant increase in Understanding (U) from pre (M = 3.60, SD = 0.98) to post (M = 3.92, SD = 0.84); t(32) = −1.90, p = 0.07. Step count difference was not significant. Physical activity awareness difference was not significant | NR | NR | Participants responded to 96% of all initial questions and to 90% of the follow-up questions sent by the system. 16 out of the 33 participants elected to continue using the system for 2 additional weeks without reward. | NR | NR | No significant changes were observed between pre- and post measurements | ||