Native speakers in all countries managed the focus groups. Coordination among the three groups was agreed upon via telephone and email contact prior to commencing the study, and a facilitator with training in clinical psychology led each group. None of the facilitators were directly involved in the clinical care of the participants. All facilitators were female, apart from those in Spain, where the facilitators were a man and a woman. Notably, these characteristics may have influenced the collection and interpretation of data. To reduce some of this bias, the coding was replicated by a qualitative researcher who was not present in the focus group and did not have a background of clinical psychology. Disagreements in coding were resolved as a pair, and a joint decision was made about the allocation of a code to each quotation.

Participants were eligible if they were above the age of 18 years and were currently experiencing clinically significant symptoms of major depressive disorder

or had experienced such symptoms in the past 2 years. Individuals with a history of a psychotic disorder, including bipolar disorder and schizoaffective disorder, and substance misuse in the last 6 months were excluded. Participants were recruited via different sources in the three countries. In the United Kingdom, potential participants were screened telephonically by using a self-report measure of depression (World Health Organization’s Composite International Diagnostic Interview - Short Form [15]). In Spain and Italy, clinicians selected patients diagnosed with major depressive disorder, who attended psychiatric services. Participants were identified by convenience sampling and their eligibility to participate. All participants provided written informed consent to participate in this study.

The discussion was semistructured using a prespecified topic guide (available on request) that was designed to elicit discussions about barriers to and facilitators of engagement with mHealth technology in the context of living with a long-term mental health condition. The open-discussion format allowed people to share a range of examples. Each group discussion lasted for 60-120 minutes. This format was developed and tested in the United Kingdom, where a second focus group with the same participants was conducted to validate the emerging findings.

Focus group discussions were audio recorded and transcribed verbatim. Both the Italian and Spanish transcripts were translated into English, allowing combined analyses by two researchers working independently with the use of the software package NVivo (version 10; QSR International, Melbourne, Australia). Subthemes emerging from the data were identified in the final analysis.

Lack of motivation was noted in all countries. Some participants spoke about reduced motivation during depression as “when I get in a downer, part of the issue is that I just cannot get on with anything” (UK24). In relation to remote measurement, one participant said, “I had to fill it in, in the morning, afternoon and evening. I did it for the first two days, then the third I did just at morning and afternoon and then stop, I didn’t do it anymore” (IT6).

A subtheme of poor insight into the health status emerged across the United Kingdom and Spain; a participant stated, “I don’t always realise that I’ve suffered a dip or a rise” (SP8).

The impact of difficulties with cognition that caused problems with memory, reading, and expression was only mentioned in Spain. Single participants in the United Kingdom and Italy mentioned that they might be forgetful, but they did not attribute this to cognitive difficulties.

Participants discussed aspects that would provide a utility and facilitate use. A function was deemed useful if the technology could motivate action, for example, “go for a walk...do some meditation” (UK2), or “call your doctor” (UK5):

One participant in the United Kingdom said that this type of feedback might help to think more positively; another suggested that it could lead to a sense of achievement. Some thought that mHealth technology was novel and enjoyable besides useful.

Raising awareness and understanding of one’s health emerged as themes from the UK group. One person said “by measuring, you might discover things that people are not aware of already” (UK24). Feeling a sense of control and providing opportunities for connection with others may have further utility, as would using prompts or alerts to improve health and safety as, for example, a way to respond to symptoms early:

Sharing data with healthcare professionals was considered a way of improving care by this individual and others in the Spanish and UK groups. In the Italian group, health monitoring was considered reassuring.

Participants felt that technology played a role in simplifying activities and serving a purpose; one participant noted, “if there is a purpose, if it simplifies my life, I am glad to use it” (IT6). There were discussions about the pros and cons of wearing devices that doubled up as watches. The participants believed that technology should easily fit within a daily routine. Practical challenges were noted, such as losing opportunities to log data due to the appearance of notifications at inconvenient timings, the need for charging, and the loss of connection.

The financial expense associated with the devices was a potential moderator of accessibility, and practical issues including lack of equipment were considered a barrier. Even if technology was available, for it to be accessible, resources need to be tailored or personalized to meet the specific requirements of individuals. When a person feels more unwell than usual, this issue may affect usage. Comments such as “It would depend also on the severity of symptoms, it must be adjusted” (IT4) and “it must be tailored to the person’s mood and feelings” (IT8) highlighted this point.

mHealth resources should be easy to use and not “fiddly” (UK24). To reduce the effort needed to engage in surveys, one participant said, “I’d prefer something that is very short that I can complete within a minute” (UK20). Simplicity and low effort appear to be key facilitators, whereas complicated features or poor design were barriers:

Wearable monitors were endorsed, and the ability to visualize data was declared important for usability.

Almost half the themes were similar across at least two countries, suggesting replication and an acceptable level of data saturation [16]. A core group of themes was repeated across all countries: the need for motivation , the potential negative impact on anxiety and mood, the inconvenience of too-frequent notifications, and the importance of ease of use. A number of key differences regarding additional subthemes emerged between regions. First, although the UK group provided an extensive list of utility examples, they were skeptical about the use of mHealth technology. Similarly, the Spanish participants had many issues with perceived utility. In contrast, the Italian group focused more on perceived costs. Participants in Spain were the only group to trust the experts. The UK group was uncertain about the digital skills and availability of resources in clinical practice. Acceptance of technology from the perspective of other people in their health systems, such as clinicians, was not raised as a concern in Spain or Italy. One older participant textboxin Italy expressed the inability to access equipment. Second, issues regarding usability were discussed in greater depth in the UK group. Although the ease of use was the only subtheme in the Italian and Spanish groups, some specific suggestions about data visualization, length of assessments, and the ease of wearables emerged in the UK group. Few technology-related barriers and facilitators emerged in Spain, where participants focused more on health-related and user-related themes than technology-related themes.

In this study, 3 major, 14 minor, and 58 subthemes emerged from the data; some were related to functionality of technology and others were about users’ abilities, perceptions, and attitudes toward technology. These nonfunctional requirements have been reported previously [17]. Our nonfunctional requirements were categorized as health-related and user-related barriers and facilitators (Figure 1).

In terms of health-related barriers and facilitators, the severity of symptoms may moderate engagement with mHealth technology. Low motivation and intermittent poor insight and memory are known to be symptoms of depression and may be specific to this population [18], which may affect mHealth systems that require direct interaction with an app as well as users’ decisions to wear devices. However, the absence of data could be as informative as its presence in algorithms created to identify the risk of relapse.

In terms of user-related barriers and facilitators, participants’ attitudes toward mHealth technology affected their engagement. Similarly, digital literacy moderates the use of technology [19], and as the results of this study suggest, affects all users including the healthcare providers who support patients. Familiarity with technology and employment regulations may either further facilitate technology adoption or pose a barrier for use.

Our participants emphasized the importance of weighing costs against utility in order to make a decision about the overall value of mHealth technology. Utility included factors such as opportunities to connect with others; prompts; raising awareness and understanding; a sense of control; and responding to early warning signs by, for example, supporting clinical decision making. Perceived costs included reduced privacy and security; lack of availability and limited resources to support use; increased health anxiety or dependency; and expending time and effort, especially if there were inaccuracies in measurement.

Previous research demonstrated a relationship between perceived convenience and usability, and the acceptance of technology [20]. Similarly, mHealth technologies were thought to be easier to accept if they reduced effort, served a clear purpose, fit into one’s daily routine, were comfortable, and promoted choice or control. Barriers included the receipt of notifications at inconvenient times and the need to charge devices or fix technical malfunctions. In addition to convenience and usability, previous literature has advocated the development of resources that are accessible or equally available to all users (eg, “universal design”) [21], and this work has reiterated the need for such development with respect to depression-specific symptoms.

The subthemes that emerged from multiple countries demonstrate some of the most important considerations for developing mHealth resources across Europe. Motivation is a key moderator of engagement. Two barriers across countries were the potential negative effect on anxiety and mood and the inconvenience of too-frequent notifications , which may be related. Focus on an easy-to-use design was clear. Some differences between the countries may relate to diversity in health care experience and the availability of or familiarity with mHealth technology. There is variation in the percentage of adults using mobile phones and internet-based technologies across Europe; Italy has lower access to these technologies than Spain and the United Kingdom [22]. Varied familiarity with mHealth technology may account for fewer examples of utility and greater concerns about potential costs in Italy, where some people may not be fully aware of the benefits and may have raised potential concerns about the loss of human interaction.

Results from this study are similar to those of a systematic review on barriers to and facilitators of engagement with remote measurement technology [13]. However, our study focused on the attitudes of individuals with depression toward technology and the nonfunctional, rather than functional, factors. Motivation was clearly an important category, but was incorporated into health-related barriers and facilitators in this study, due to the inextricable link between mood and emotional resources for people with depression; their physical abilities were never discussed. Although a few previous studies reported the acceptability and feasibility of mHealth resources for people with mental health conditions (eg, [23-26]), none of them explored barriers and facilitators across several countries.

This study uniquely provides views from participants living in different countries and revealed both similar and potentially different issues that were considered by the different groups. Although mHealth resources should take into account the similarities of views, it is essential to continue monitoring engagement across different countries, as these differences may affect their efficient implementation.

Strengths of this study were the inclusion of a varied sample that represented three European countries that place similar emphasis on community-based or “remote” treatment interventions for mental health. The qualitative approach enabled a rich, in-depth discussion of possible barriers to and facilitators of engagement with mHealth technology. It was not constrained to responses to specific questions, which allowed the discovery of themes that may not have emerged otherwise.

Although another strength of the study was the cross-national approach to understand factors influencing engagement, it is important to note that the translation may have influenced the findings. A further key limitation is the dependence of our results on hypothetical scenarios rather than actual experience. We have identified several themes that can guide research design and technological development, but we should be cautious about the anticipated risks or benefits that may not be sustained when people are exposed to technology. Further user testing with specific prototypes is required to maximize acceptability and usability. Such user testing will include a wider sample of the population with a history or current symptoms of depression, which will involve purposive sampling.

Future research should consider other stakeholders. Craven et al [17] advocate the involvement of all possible end users including carers and clinicians, which may result in systems that are easily implemented in practice. A few studies that implemented this holistic perspective and involved several users [27] found commonalities in terms of universal support for technology innovation and potential barriers to the use of mHealth technology, similar to those identified in this study.

This qualitative study investigated the potential barriers to and facilitators of engagement with mHealth technology. A number of functional and nonfunctional categories emerged with both similarities and differences across European countries. The themes form a platform for future research on engagement with mHealth technology as a part of healthcare. A number of hypotheses have been generated: Increased familiarity and perceived utility, improved choice and control, greater convenience and accessibility, and lower intrusiveness may influence decisions about the use and engagement of mHealth technology and should be encouraged and evaluated in future studies, as the data might provide useful to improve existing models.