Cost-effectiveness of early intervention in psychosis in Latin America: economic evaluation of Chilean services

BACKGROUND: International evidence suggests that Early Intervention for Psychosis (EIP) services are both effective and cost-effective. Such evidence, however, comes almost exclusively from high-income countries. AIMS: Our aim was to estimate the cost-effectiveness of EIP services in a Latin American setting. METHOD: We compared EIP services against community mental health teams (CMHT) from the Chilean health system perspective. We developed a six-state Markov model to estimate the costs, benefits (measured as quality-adjusted life-years (QALYs)) and incremental cost-effectiveness ratio (ICER) for a 10-year time horizon. The model was populated with data from a Chilean EIP cohort, published literature and expert opinion. We characterised uncertainty through probabilistic sensitivity analysis and calculated the value of information to reduce such uncertainty. RESULTS: In the base case analysis, EIP was cost-effective compared with CMHT, with an ICER of 5 550 044 Chilean pesos per QALY (USD 13 742 adjusted for purchasing power parity). Uncertainty analysis revealed an 80% probability of EIP services being the most cost-effective option at a willingness-to-pay threshold of one gross domestic product per capita (USD 15 923). Sensitivity analysis showed that the results were sensitive to parameters such as intervention effectiveness and cost, suggesting that a new trial might be worthwhile to reduce uncertainty. CONCLUSIONS: This model suggests that implementing EIP services in Chile may cost more, but it is likely to be cost-effective. Nonetheless, more evidence about affordability, equity and broader perspectives is needed to improve the economic case of implementing EIP services in less-resourced settings, such as in Latin America.