Table 4.

Studies on virtual coaching applied to clinical or medical contexts included in the analysis as exploratory studies.

Paper reference	Study aim	Outcome measurement	Conclusion
Guillen et al 2005 [33]	Assess technological platform and the fitness condition.	Heart rate; VO2	The coach is based on the personalized training programs adapted to user’s characteristics and preferences and on a continuous assessment of the actual fitness status.
Segerståhl et al 2011 [34]	Investigate how users incorporate a system employing 2 modes of delivery into their training and analyze benefits in personal exercise monitoring.	Heart rate	Personal exercise monitoring systems may be improved by more systematically combining mobile and Web-based functionality.
Cotè et al 2012 [35]	Study of the acceptability and feasibility of a Web application which was designed to empower people living with HIV to manage their daily antiretroviral therapies	Acceptability questionnaires; field notes; observations	The results of the study support the feasibility and acceptability of the intervention.
Novielli et al 2012 [36]	Investigate the user’s reactions to received suggestion by an embodied conversational agent (ECA) playing the role of artificial therapist in the healthy eating domain	Classification of speech; user’s reactions	The adaptation of the dialogue is crucial for an effective persuasive interaction.
Ellis et al 2013 [37]	Feasibility, acceptability, and preliminary evidence of effectiveness of a virtual exercise coach to promote daily walking in community dwelling persons with Parkinson disease.	Six-minute walk test; gait speed; number of steps per day; retention rate; satisfaction; interaction history	Sedentary persons with PD successfully used a computer and interacted with a virtual exercise coach. Retention, satisfaction, and adherence to daily walking were high over 1 month.
Hudlicka 2013 [38]	Develop and evaluate a virtual mindfulness coach for training and coaching in mindfulness meditation	Web-administered surveys 5-point; Likert scale	Virtual coach-based training of mindfulness is both feasible, and potentially more effective, than a self-administered program.
Kreps et al 2013 [39]	Describe how electronic health communication programs can be improved by using artificial intelligence to increase immediacy	Weight; patient’s activity; sleep patterns	Artificial Intelligence can enhance the ‘‘immediacy’’ of eHealth by humanizing health promotion efforts, promoting physical and emotional closeness.
Silveira et al 2013 [40]	Investigate which information technology-mediated motivation strategies increase adherence to physical exercise training plans in older people	Adherence and attrition; gait speed; motivation instruments	The social motivation strategies were more effective to stimulate the participants to comply with the training plan and remain on the intervention.
van Vuuren et al 2014 [41]	Analysis of performance of a system for delivering speech and language therapy to people with aphasia, delivered by a virtual therapist	Performance in terms of word accuracy	For persons with aphasia, receiving treatment in an ecologically valid real-world setting delivered by a virtual therapist that provides more cues than not can lead to faster learning.
Adams et al 2015 [42]	Investigate how modify desired movements and activities in a way that minimizes shoulder joint abduction, extension, and flexion	Blood pressure; amount of work done in weight training	The VC, based on a sport-specific, symptom-limited exercise program, would enable the patient to train at a higher intensity than is typically allowed.
Cotè et al 2015 [43]	Explore and describe how patients living with HIV experience receiving customized asynchronous accompaniment via a virtual nurse	Semistructured interviews to get participants to share their experience of the intervention through personal stories and what they thought and felt during their participation	The virtual nurse humanized the experience and helped them acquire new skills for achieving optimal antiretroviral therapy adherence.
Stevens et al 2016 [44]	Investigate the effect of features of human behavior on the quality of interaction with an ECA	Number of errors in ECA speech; multiple-choice questions	Influences from mimicry can be explained by visual and motor simulation, and bidirectional links between similarity and liking.
Tielman et al 2017 [45]	Study the preferable presentation mode for improving adherence.	Behavioral data; questionnaires	Both the attitude towards the virtual agent and how well the psychoeducation was recollected were positively related to adherence in the form of task execution.
Chi et al 2017 [46]	Examine the perceived acceptance and utility of a tablet-based ECA (termed digital pet) for older adults	Semistructured, individual interviews for testing of a digital pet companion	A digital pet can provide older adults with companionship and enhance social interaction.
Gabrielli et al 2017 [6]	Describe the design and development of a nutrition education app and the results of a formative evaluation with families	Knowledge of the Mediterranean diet; URICA (University of Rhoda Island Change Assessment)-short-form scale; intention to use technology for nutrition education	The user-centered design showed that nutrition education apps are feasible and acceptable solutions to support health promotion interventions in primary care.
Klaassen et al 2018 [47]	See how patients with type 1 diabetes experience the game with a VC	System Usability Scale; semistructured interview to explore user experiences	User evaluations with patients under pediatric supervision revealed that the use of mobile technology in combination with Web-based elements is feasible.
Oyibo et al 2018 [48]	Evaluate determinants of bodyweight exercise performance in the context of behavior modeling in fitness apps	Social cognitive theory instruments	The study provides a set of guidelines for the design of persuasive technologies for promoting regular exercise behavior.
Richards et al 2018 [49]	Evaluate a novel approach that involves a website and virtual specialist for patients while they are awaiting their specialist appointment	Cross-cultural continence-specific quality of life; Pediatric Incontinence Questionnaire; ehealth literacy survey (eHEALS) ; Newest Vital Signs test; Working Alliance Inventory	A novel approach that involves a website and virtual specialist for patients while they are awaiting their specialist appointment showed an overall improvement in 74% of patients with urinary incontinence.
Suganuma et al 2018 [50]	Use an internet-based cognitive behavioral therapy preventative mental health measure	World Health Organization-Five Well-Being Index; Kessler 10; Behavioral Activation for Depression Scale	The internet-based cognitive behavioral therapy with the embodied conversational agent can be used in mental health care.
Dworkin et al 2019 [51]	Evaluate the feasibility, acceptability, and preliminary efficacy of an ECA intervention to improve adherence to antiretroviral therapy	Adherence; acceptability; feasibility, pre- versus posthealth literacy; pre- versus post-self-efficacy	The pilot study of demonstrated acceptability and preliminary efficacy in improving adherence in this important population.
Srivastava et al 2019 [52]	Evaluate performance relative to behavior stages associated with long-term behavior modification	Continuity in adherence to the program	The strength of the physician–patient relationship appears to allow people with prediabetes to skip or advance rapidly through behavioral stages in the process of lifestyle modification.