Background Digital contact tracing (DCT) apps have been implemented as a response to the COVID-19 pandemic. Research has focused on understanding acceptance and adoption of these apps, but more work is needed to understand the factors that may contribute to their sustained use. This is key to public health because DCT apps require a high uptake rate to decrease the transmission of the virus within the general population. Objective This study aimed to understand changes in the use of the National Health Service Test & Trace (T&T) COVID-19 DCT app and explore how public trust in the app evolved over a 1-year period. Methods We conducted a longitudinal mixed methods study consisting of a digital survey in December 2020 followed by another digital survey and interview in November 2021, in which responses from 9 participants were explored in detail. Thematic analysis was used to analyze the interview transcripts. This paper focuses on the thematic analysis to unpack the reasoning behind participants’ answers. Results In this paper, 5 themes generated through thematic analysis are discussed: flaws in the T&T app, usefulness and functionality affecting trust in the app, low trust in the UK government, varying degrees of trust in other stakeholders, and public consciousness and compliance dropping over time. Mistrust evolved from participants experiencing sociotechnical flaws in the app and led to concerns about the app’s usefulness. Similarly, mistrust in the government was linked to perceived poor pandemic handling and the creation and procurement of the app. However, more variability in trust in other stakeholders was highlighted depending on perceived competence and intentions. For example, Big Tech companies (ie, Apple and Google), large hospitality venues, and private contractors were seen as more capable, but participants mistrust their intentions, and small hospitality venues, local councils, and the National Health Service (ie, public health system) were seen as well-intentioned but there is mistrust in their ability to handle pandemic matters. Participants reported complying, or not, with T&T and pandemic guidance to different degrees but, overall, observed a drop in compliance over time. Conclusions These findings contribute to the wider implications of changes in DCT app use over time for public health. Findings suggest that trust in the wider T&T app ecosystem could be linked to changes in the use of the app; however, further empirical and theoretical work needs to be done to generalize the results because of the small, homogeneous sample. Initial novelty effects occurred with the app, which lessened over time as public concern and media representation of the pandemic decreased and normalization occurred. Trust in the sociotechnical capabilities of the app, stakeholders involved, and salience maintenance of the T&T app in conjunction with other measures are needed for sustained use.

BACKGROUND Digital contact tracing (DCT) apps have been recently implemented widely as a response to the Covid-19 pandemic. Research has focused on understanding the acceptance and adoption of these apps, but more work is needed to understand which factors may contribute to sustained use of the app. This is key in public health due to DCT apps needing a high uptake rate to decrease transmission of the virus within the general population. OBJECTIVE To understand changes in use of the NHS Test & Trace (T&T) Covid-19 DCT app and to explore how public trust in the app evolved over a one-year period. METHODS A longitudinal mixed-methods approach was conducted consisting of a digital survey in December 2020 followed by another digital survey and interview in November 2021 in which survey responses from 9 participants were explored in detail. Thematic analysis was used to analyse interview transcripts. This paper focuses on the thematic analysis of the qualitative data to unpack the reasoning behind participants answers to the surveys. RESULTS In this paper, five themes generated through thematic analysis are discussed in detail: flaws of the T&T app; usefulness and functionality affecting trust in the app; low trust in UK government; varying degrees of trust in other stakeholders; and public consciousness and compliance dropping over time. Twenty subthemes were developed within these themes. Mistrust evolved from participants’ experiencing sociotechnical flaws of the T&T app and led to concerns over the app’s usefulness. Likewise, mistrust in the government was linked to perceived poor pandemic handling and creation and procurement of the T&T app, including data management. However, more variability in trust in other stakeholders was highlighted, dependent on perceived competence and intentions. For example, Big Tech companies (i.e. Apple, Google), large hospitality venues, and private contractors were seen as more capable, but participants mistrust their intentions, and small hospitality venues, local councils and NHS (i.e. public health system) were seen as well-intentioned but there is mistrust in their ability to handle pandemic matters. Finally, participants reported complying –or not– with T&T and pandemic guidance to different degrees, but overall observed a drop in compliance over time, both at individual and external levels. CONCLUSIONS The findings of this research contribute to the wider implications of sustained app use for public health. Findings suggest that trust in the wider T&T app ecosystem is needed for sustained use of the app. Initial novelty effects occurred with the T&T app, which lessened over time as public concern and media representation of the pandemic decreased and normalisation occurred. Trust in the sociotechnical capabilities of the app, stakeholders involved, and maintaining salience of the T&T app in conjunction with other measures are needed for sustained use.

The home is becoming a key location for healthcare delivery, including the use of technology driven by autonomous systems (AS) to monitor and support healthcare plans. Using the example of a smart mirror, this paper describes the outcomes of focus groups with people with multiple sclerosis (MS; n=6) and people who have had a stroke (n=15) to understand their attitudes towards the use of AS for healthcare in the home. We thematic analysis to analyse the data. The results indicate that the use of such technology depends on the level of adaptability and responsiveness to the users’ specific circumstances, including their relationships with the healthcare system. A smart mirror would need to support manual entry, responsive goal setting, effective aggregation of data sources and integration with other technology, have a range of input methods, be supportive rather than prescriptive in messaging, and give the user full control of their data. Barriers to adoption include a perceived lack of portability and practicality, lack of accessibility and inclusivity, a sense of redundancy, being overwhelmed by multiple technological devices, and a lack of trust in data sharing. These results inform the development and deployment of future health technologies based on the lived experiences of people with health conditions who require ongoing care.