Cost-Effectiveness of Atypical Antipsychotics in the U.K.

This article, published in Value in Health, describes an adapted version of an earlier published discrete event simulation (DES) model that aims to estimate the cost-effectiveness of atypical relative to conventional antipsychotics for the treatment of schizophrenia in the UK. Over a 5-year period, the disease and treatment history of the patients is monitored in terms of symptoms (using the Positive and Negative Symptom Score [PANSS]), psychiatrist visits, pharmacological treatment and treatment location, number and duration of psychotic relapses, level of compliance, quality-adjusted life years (QALYs), and side effects. Costs estimates include direct costs of medication, psychiatric visits, and costs associated with residing in specific treatment locations (e.g., community treatment, staffed hostel, or hospital). The DES model was programmed using Extend software.

The results indicate that when comparing conventional and atypical antipsychotics, the latter decreases 5-year costs by £1633 per patient and results in a QALY gain of 0.101. The probabilistic sensitivity analysis suggests that these results are robust. The sensitivity analyses indicates that incremental costs and effects are most sensitive to the differential efficacy of atypicals and conventionals, as measured by PANSS. Under the assumption that the only differences between atypicals and conventionals are found in side-effect profiles, the incremental cost-effectiveness ratio of the atypicals is £45,000 per QALY gained.

Considering a willingness-to-pay threshold of £30,000 per QALY, the authors conclude that atypical antipsychotics are cost-effective compared to the conventional antipsychotics in the treatment of schizophrenia in the UK.