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.