Table 2 Summary of study and sample characteristics
No. | First author/published year/Country | Primary Aim(s) | Study design/# of groups | Theoretical framework | Sample characteristics | ||||
|---|---|---|---|---|---|---|---|---|---|
Total Size (N)/Attrition (%) | Mean age (SD) years and/or range | Females/ Women % | Race/ Ethnicity % | Education/Income | |||||
Randomized controlled trials | |||||||||
1 | Kramer J/a 2020/Switzerland [31] | To evaluate the effects of the Ally chatbot that combines financial incentives, weekly planning, and daily self-monitoring prompts on reaching daily step goals. | Optimization randomized trial/1 group micro-randomized to incentive (cash vs. charity vs. no incentive) X Planning (action vs. coping vs. no planning) X Self-monitoring prompt (prompt vs. no prompt) groups. | Health Action Process Approach | N = 274/30.3% | 41.7 (13.5)/NR | 57.7 | NR | 59.9% with university degree |
2 | Kunzler F/b2019/Switzerland [33] | To explore the factors affecting users’ receptivity towards Just-In-Time Adaptive Interventions (JITAIs) delivered via the Ally chatbot. | Randomized controlled trial/ 3 groups (cash bonus vs. charity donation vs. control) | NR | N = 189/NR | 40.0 (13.7)/NR | 63.0 | NR | NR |
3 | Piao M/ 2020/ South Korea [32] | To assess the efficacy of the Healthy Lifestyle Coaching Chatbot intervention presented via a messenger app aimed at stair-climbing habit formation for office workers. | Randomized Controlled Trial/ 2 groups (intervention vs. control) | Habit Formation Model | N = 106/12.3% | NR/20-59 | 56.7 | NR | NR |
4 | Carfora V/2019/Italy [34] | To test a chatbot that delivers daily messaging intervention aimed at promoting the reduction of red and processed meat consumption (RPMC). | Randomized Controlled Trial/3 groups (informational vs. emotional vs. control) | NR | N = 180/8.0% | 20 (2.0)/NR | 75.6 | NR | 100% Undergraduate students |
Non-randomized studies | |||||||||
5 | Maher CA/2020/Australia [20] | To test the feasibility (recruitment and retention) and preliminary efficacy of physical activity and Mediterranean-style dietary intervention (MedLiPal) delivered via an artificially intelligent virtual health coach. | Quasi-experiment/1 group | NR | N = 31/9.7% | 56.2 (8.0)/45-75 | 67.7 | NR | NR |
6 | Fadhil A/2019/NR [35] | To present the design and validation of CoachAI, a conversational agent-assisted health coaching system on physical activity, healthy diet, and stress coping. | Quasi-experiment/1 group | Health Action Process Approach, Technology Acceptance Model, AttrakDiff Model | N = 19/NR | 28.5 (9.4)/19-53 | 42.1 | NR | Most were university students or had graduate degree |
7 | Stephens TN/2019/U.S. [21] | To assess the feasibility of integrating the Tess chatbot in behavioral counseling of adolescent patients coping with weight management and prediabetes symptoms to promote treatment adherence, behavior change, and overall wellness. | Quasi-experiment/1 group | Cognitive Behavioral Therapy, Emotionally Focused Therapy, Behavioral Activation, Motivational Interviewing | N = 23/NR | 15.2 (NR)/9.78-18.54 | 57.0 | Hispanic (43%), White (39%), Black (9%), Asian (9%) | NR |
8 | Casas J/ 2018/ Switzerland [36] | To evaluate the effects of a conversational assistant designed to monitor and coach participants to achieve specific goals regarding their diet. | Quasi-experiment/1 group | NR | N = 36/NR | NR | NR | NR | NR |
9 | Kocielnik R/ 2018/ U.S. [37] | To develop and examine the feasibility of a mobile conversational system, Reflection Companion, to engage users in reflection on physical activity through dialogues | Quasi-experiment/1 group | Structured Reflection Model | N = 33/NR | 36.5 (11.2)/21-60 | 87.9 | NR | 55% college degree or being enrolled in college, 27% graduate degree |