Table 3.

Summary of barriers from all studies.

Themes and subthemes		Findings		Illustrative quotes
2. Barriers
	2.1 Technological issues are prevalent, causing disruption and limits to high-quality and secure service delivery
			Connectivity. Challenges because of problematic client and/or therapist internet connection, video conferencing hardware and software, or problems with server connection commonly present difficulties establishing and maintaining a clear, audible, and uninterrupted video-feed impacts the quality of service delivery and client satisfaction		“The majority of the technical problems that were reported involved lost wireless signals or video or audio quality issues, such as a delay in picture or sound due to poor Internet connection.” [25] “...technical issues with initiating and maintaining a videoconferencing connection were more frequent than expected...” [88]
			Hardware that is compatible for securely connecting with encrypted video conferencing software is not always available for clients. Additionally, as many participants in the studies were provided hardware, more knowledge regarding the protocols and optimal infrastructure for secure delivery of digital health services using personal and/or private computers or video conferencing compatible devices is needed		“An ideal capability would be to use a network infrastructure that meets U.S. Department of Defense network security requirements but that also allows for the use of privately owned end-user equipment (ie, personal computers, Webcams, mobile devices, etc.).” [88]
	2.2 Perceptions of digital health services may limit client acceptance and openness
			Openness to digital health use may depend on previous experiences or recommendations from trusted individuals or sources. Veterans were described as being hesitant to try new technologies because of issues of security or inconsistency with lifestyle (especially in rural populations). As the studies included clients who were seeking services and open to digital health delivery, more knowledge is yet needed of this population’s perceptions and acceptance of digital health services		“Clinical experience, however, suggests that many patients are hesitant to try new technologies.” [55]
	2.3 Challenges to client privacy, comfort, and safety exist because of client environment and remote nature of service delivery
			Lack of a quiet, private space in which clients can engage in therapy without the fear of being overheard by family members or roommates is common		“... advantages [of digital health] must be balanced by potential shortfalls, such as lack of privacy from family members when televideo sessions are conducted into homes where soundproofing between rooms may not be in place.” [87]
			Session disruptions by doorbells or experiencing an abrupt transition back into everyday life after logging off a session made it difficult to engage from the home environment		“That’s why it was hard to switch from talking all about it and then sort of, the hour’s up and then you’ve got to try and get on with normal life.” [85]
			Some clients indicated discomfort with communication over video despite satisfaction with their therapist. Concerns about managing strong emotions evoked in therapy in an isolated home environment lead clients to prefer in-person treatment. Additionally, clients may be less trusting of the privacy and confidentiality of digital health services		“I do not like not knowing who else is in the room with the therapist.” [55]
			Safety is difficult to manage in a clinically unsupervised environment where a client may be at risk of purposefully terminating a teleconference session while being at risk of suicide. Much of the reviewed literature excluded clients who posed a risk for suicide, and therefore more examples and knowledge on managing risk and responding to a crisis are necessary. Establishing safety protocols involving family members or neighbors and adjusting service delivery schedules to accommodate is a commonly reported measure; feasibility and ethics in doing so must be considered		“Potential drawbacks include... the difficulties of ensuring patient safety in a clinically unsupervised environment.” [55]
	2.4 Limits to the therapeutic alliance and intervention activities may impact clinical utility and effectiveness
			Establishing and building the therapeutic alliance necessary for effective treatment may be challenged because of the impersonal feeling of videoconferencing, which is influenced by an inability to read all the client and therapist nonverbal body cues		“Despite being able to see the therapists face, several participants reported that they felt that doing therapy over Skype felt impersonal because they weren’t in the same room.” [85]
			Therapist comfort with digital health may impact the selection of treatment modalities. Further, some clients may benefit from the in-person presence of a clinician to complete exposure activities as per a treatment protocol. Clients with hypervigilance may be unwilling to close eyes during imaginal exposure as they are not reassured that a therapist can watch out for and respond to threats in their environment. Secure exchange of information online related to intake, assessment, and client homework remains an issue		“Patients who present with more severe symptoms or extreme hypervigilance may be harder to treat via telehealth.” [58]
	2.5 Ease of disengagement with services and enablement of social avoidant behaviors may be enhanced
			Clients can disengage quickly and easily if a session becomes too challenging or uncomfortable. They may engage in distractions during the session, such as watching television or browsing the internet		“if you’re having a bad session, you can just switch him off and walk out the room easily.” [51]
			Enablement of socially avoidant behaviors may occur when delivering mental health service to a client in their home. Care is required to ensure digital health delivery is not discouraging clients from engaging in healthy life events		“...Veterans may require leaving their home and attending face-to-face sessions as part of the therapeutic process.” [59]