Early Intervention (EI) in psychosis is a complex intervention usually delivered in a specialist stand-alone setting, which aims to improve outcomes associated with psychosis. This study evaluates whether EI services provide a net benefit to the health sector when the service is delivered in a real world setting in comparison to best practice community mental health (CMH) treatment. The study evaluates two contemporaneous cohorts presenting with a first episode of psychosis, one to an EI service and the other to a CMH service. The evaluation is conducted from the perspective of both the health service and the wider societal perspective.
We find that EI reduces inpatient costs, increases CMH costs and has a modest probability of being cost-effective from the perspective of the health sector. However, from the societal perspective, EI delivers a large Net Benefit (NB) to society and there is a high probability that it cost-effective. From the health sector perspective, the unadjusted NB of EI was €1,796 and the probability that EI was cost-effective was 0.702 when society placed no value on preventing a relapse that required inpatient admission or home care. Following adjustment for covariates, the probability that EI was cost-effective was 0.587. EI achieved an 80% probability of being cost-effective once the value placed on avoiding a relapse was €5,500.
When the study was re-analysed from the societal perspective, the NB of EI rose to €32,581 and the probability that EI was cost-effective was 1, even when society placed no value on preventing a relapse. Following adjustment for covariates, the NB of EI was €13,253 and the probability that EI was cost-effective was 0.901. The choice of outcome measure and perspective of the study are critical when presenting the results of an evaluation of EI to policymakers and service planners.
