Table 2.

Case studies illustrating how the distinctive features of the DHI were incorporated into the economic evaluation

Methodological issue	Digital health intervention	How the distinctive feature of the DHI was incorporated into the economic evaluation
Comparator	The HeLP-Diabetes programme [23]: internet-based intervention to support self-management of type 2 diabetes in England. The intervention included an educational, interactive website, with behaviour change support, emotional support and training sessions to facilitate access to the HeLP-Diabetes tool	The intervention was designed as an addition to current practice, which might have included general information provided by the GP or available online. The comparator group was defined as publicly available online information based on both Diabetes UK and NHS Choices websites. To help comparability between the intervention and ‘usual practice’, participants in the control group were also given an introductory facilitation meeting to help them navigate these websites and an information booklet to take home
Product evolvement	Down Your Drink [27]: internet-based intervention to support behaviour change in people with hazardous alcohol consumption. This consisted of an online interactive programme (weekly interaction to read materials and complete exercises) based on cognitive behavioural techniques	Following user feedback, major components associated with the development of new modules and features to improve the attractiveness and functioning of the website had to be introduced. This included re-structuring website components, adding new features to improve user interaction and implementing a new incentives system. As a result, the additional costs involved with user-led redevelopment led to the intervention cost being twice as big as that initially estimated [45]
User involvement	Digital smoke cessation programme [46]: web-based intervention to support smoking cessation, with or without counselling. The economic evaluation included cost impacts to the patient arising from active user involvement	Data were obtained by measuring and costing (i) the resources associated with travel to smoking cessation sessions and time spent engaging with the smoking cessation digital platform, (ii) informal care, which accounted for potential additional support by the caregiver to interact with the website. On the outcomes side, any health impacts resulting from user involvement were assumed to be captured in the patient-reported quality of life outcomes
Intervention cost	The Link tool [47]: web-based mental health navigation tool (Link) to guide young adults with severe mental distress to appropriate online and off-line sources of mental health information and care. The web platform has been developed exclusively for this intervention	Development costs were included and were very high (AU$1.74 million) compared to the maintenance costs (AU$29,803). The marginal cost of providing Link was essentially zero, and hence the study used an estimate of the population likely to receive the intervention and uptake rates to estimate the mean cost per user. This led to a low cost per user (around AU$5)
Benefit assessment	The ESTEEM programme [48]: online triage system, led by either a GP or nurse, for managing same-day consultations in primary care. The economic evaluation considered both health and non-health benefits of new digital patient management system	Non-health benefits included aspects related to system efficiency (e.g. health care contacts required to treat patient), user experience (e.g. care readiness), wellbeing (convenience of care) and problem resolution. While differences in patients’ health status (EQ-5D-3L) were small between consultation systems, GP and nurse-led online triage led to much higher patient satisfaction and problem resolution scores
Non-health care impacts	Web-based perioperative recovery [49]: Bouwsma and colleagues developed and assessed a web-based care programme to facilitate recovery of women undergoing gynaecological surgery. This digital intervention was anticipated to have a significant impact on women’s ability to return to work	Study adopted societal perspective and included a broad range of non-health care costs and benefits associated with swifter return to work. This involved quantifying the time to ‘sustainable return to work’ and any costs savings associated with both absenteeism and presenteeism. Absenteeism and presenteeism costs were calculated using the human capital approach (equivalent to sick leave costs). The productivity-related costs (£8443) represented about 70% of the total cost of the intervention (£12,266) and drove the cost savings (− £647) of the DHI compared with usual care
Economic analysis	The ESTEEM programme [48]: online triage system, led by either a GP or nurse, for managing same-day consultations in primary care. This study nicely illustrates how CCA can help inform decision making when non-health benefits are of prime interest to the target population	CCA allowed decision makers to assess relative value for money of the new digital patient triage system according to the benefits they wish to prioritise. For example, if the priority was to benefit overall GP workload, then GP or nurse-led online triage was unlikely to be cost effective compared with standard telephone triage, because it just changed the nature of that workload. Conversely, if the decision maker was more interested in benefits in terms of reducing GP visits, nurse-led online triage was likely to provide good value for money

CCA cost-consequences analysis