Prevention of dementia using mobile phone applications (PRODEMOS) – a health-economic cost-utility analysis in people aged 55–75 years with low socio-economic status

• The PRODEMOS coach-supported mobile health intervention for the primary prevention of dementia, aimed at people aged 55 to 75 years with low SES in the UK and those of any SES in China, may potentially lack cost-effectiveness in both countries. However, the results were based on strong assumptions regarding causality and sustained effectiveness, which limits policy recommendations. We aimed to explore the potential incremental cost-effectiveness of the PRODEMOS coach-supported mobile health intervention for primary prevention of dementia versus standard of care provided to people aged 55–75 years with low socio-economic status (SES) in the United Kingdom (UK), and any SES in China. 12–18-month PRODEMOS trial (ISRCTN15986016) efficacy outcomes on hypertension, obesity, hypercholesterolemia, physical inactivity and smoking were extrapolated to lifetime impact on dementia onset, myocardial infarction, stroke and death using a health-economic open-source simulation model. Simulated outcomes showed dementia cases were avoided (UK = -206 (-658 to 281), China = -140 (-456 to 205) per 100,000 persons) and disease-free time was gained for dementia, myocardial infarction and stroke (mean months per person UK = 0.4, 0.0 and 0.0; China = 0.2, 0.0 and 0.0 respectively). Assuming a maximum intervention duration of 10 years with a 10 % annual non-adherence rate, the incremental net health benefit in the UK (-0.190) and China (-0.009) indicated a potential lack cost-effectiveness. Our method was limited by strong assumptions regarding causality and sustained effectiveness, lack of some country-specific input estimates, and the lack of probabilistic analysis. The PRODEMOS coach-supported mobile health intervention for the primary prevention of dementia, aimed at people aged 55 to 75 years with low SES in the UK and those of any SES in China, may potentially lack cost-effectiveness in both countries. However, lack of data required strong assumptions regarding causality and sustained effectiveness, which limited policy recommendations.