Economic impact of services for first-episode psychosis: a decision model approach

Aim: To assess the impact of early intervention (EI) services on service costs for people with first-episode psychosis. Methods: A decision model was constructed to map the care pathways following input from EI services and from standard care. A Markov process was used to run the model over 18 2-month cycles. Probabilities and costs for the model of admissions, readmissions and use of community services were obtained from the literature, routine sources and expert opinion. One-way and probabilistic sensitivity analyses were conducted to address uncertainty around the parameter estimates. Results: The model estimated 1 year costs to be 9422 pound for EI and 14 pound 394 for standard care. The respective figures over 3 years were 26 pound 568 and 40 pound 816. One-way sensitivity analyses revealed that the results were robust to changes in most parameters with the exception of the readmission rate. A relatively small decrease in the readmission rate for standard care patients would eliminate the cost saving. The probabilistic sensitivity analyses also showed that the results were robust to parameter changes. Conclusions: This study suggests cost savings associated with EI. However, caution is required as the model is relatively simple and relies on a number of assumptions.