Cost-effectiveness of mood stabilizers and atypical antipsychotics in maintenance therapy of bipolar disorder in the Brazilian Unified Health System

Abstract

Objective: To evaluate the cost-effectiveness of the combination of atypical antipsychotic and mood stabilizers in maintenance treatment of bipolar disorder in the Brazilian Unified Health System (SUS). Methods: Taking direct costs, from the perspective of SUS, we built a Markov model with transitions between the states: euthymia, mania, depression, discontinuation and death. Data were extracted from clinical trials, prospective cohorts and SUS databases (current values of 2015). In a hypothetical cohort (n = 2,000, age = 40 years), maintenance therapy was simulated over quarterly cycles through a timeframe up to 30 years (until effectiveness < 1 day in remission). Discount rates and half-cycle correction were applied and sensitivity analyses were run. Results: The efficacy data enabled to include only a combination with quetiapine in the analysis. After twelve years (48 cycles), there were 512 acute episodes (depression: 285, mania: 227) for monotherapy with lithium or val[1]proate against 306 (depression: 166, mania 139) for the quetiapine combination. The incremental cost-effectiveness ratio (ICER) for the quetiapine combination was R$ 807.95 per additional month in remission. The sensitivity analysis demonstrated the model’s robustness, while dosage and quetiapine-price variations had most impact in ICER (ranging from R$ 541.60 to R$ 1,770.05 per additional month in remission). Conclusion: Maintenance therapy with the combination of quetiapine and lithium or valproate seems to be cost-effective. As the use of atypical antipsychotics is also associated with risks, the studied strategy can be a therapeutic alternative for specific populations in SUS.