OBJECTIVES: The Narrative Experiences Online (NEON) Intervention is a digital health intervention to improve quality of life for people with mental health problems by providing online access to mental health recovery narratives. The NEON Intervention incorporates an automated algorithmic system to generate personalised recommendations of narratives, or users can browse the collection of narratives themselves. The aim of this study was to determine the cost-effectiveness of the NEON Intervention for people with psychosis and non-psychosis mental health problems in England.

METHODS: A within-trial cost-effectiveness analysis of the NEON Intervention compared with current practice was performed alongside two definitive randomised controlled trials for people with psychosis (NEON Trial: ISRCTN11152837) and non-psychosis (NEON-O Trial: ISRCTN63197153) mental health problems. The time horizon was 12 months. The perspective was the National Health Service (NHS) England. Participants included those who had, and had not, used primary and/or secondary mental health services. Health outcomes were expressed as quality-adjusted life years (QALYs). Delivery costs of the digital health intervention were included. Participant-reported downstream health and social care costs were collected. Total QALYs and total costs for both arms were estimated by generalised linear models with multiple imputation adjusting for baseline characteristics. Sampling uncertainty was handled by bootstrapping. The primary outcome was the incremental cost-effectiveness ratio (ICER). A threshold of £20,000-£30,000 per QALY gained was used to determine cost-effectiveness.

RESULTS: The NEON Trial comprised 739 participants. The NEON-O Trial comprised 1,023 participants. For the NEON Trial, the ICER was £110,501 (incremental cost: £1,177; incremental QALY: 0.0107; probability of cost-effectiveness at £30,000 per QALY gained: 3.9%). For the NEON-O Trial, the ICER was £12,526 (incremental cost: £178; incremental QALY: 0.0142; probability of cost-effectiveness at £30,000 per QALY gained: 88.2%).

CONCLUSIONS: The NEON Intervention improved QALYs for both trial populations and is a cost-effective digital health intervention for people with non-psychosis mental health problems.