The Cost-Effectiveness of a Novel Online Social Therapy to Maintain Treatment Effects From First-Episode Psychosis Services: Results From the Horyzons Randomized Controlled Trial

Background: Digital interventions have potential applications in promoting long-term recovery and improving outcomes in first-episode psychosis (FEP). This study aimed to evaluate the cost-effectiveness of Horyzons, a novel online social therapy to support young people aged 16-27 years following discharge from FEP services, compared with treatment as usual (TAU) from a healthcare sector and a societal perspective. Study design: A cost-effectiveness analysis (CEA), based on the change in social functioning, and a cost-utility analysis (CUA) using quality-adjusted life years were undertaken alongside a randomized controlled trial. Intervention costs were determined from study records; resources used by patients were collected from a resource-use questionnaire and administrative data. Mean costs and outcomes were compared at 18 months and incremental cost-effectiveness ratios were calculated. Uncertainty analysis using bootstrapping and sensitivity analyses was conducted. Study results: The sample included 170 participants: Horyzons intervention group (n = 86) and TAU (n = 84). Total costs were significantly lower in the Horyzons group compared with TAU from both the healthcare sector (-AU$4789.59; P < .001) and the societal perspective (-AU$5131.14; P < .001). In the CEA, Horyzons was dominant, meaning it was less costly and resulted in better social functioning. In the CUA, the Horyzons intervention resulted in fewer costs but also yielded fewer QALYs. However, group differences in outcomes were not statistically significant. When young people engaged more with the platform, costs were shown to decrease and outcomes improved. Conclusions: The Horyzons intervention offers a cost-effective approach for improving social functioning in young people with FEP after discharge from early intervention services.