An Evaluation of the Variation and Underuse of Clozapine in the United Kingdom

Abstract

Background: Clozapine is the only licensed treatment for treatment refractory schizophrenia. Despite this, it remains grossly underused relative to the prevalence of refractory schizophrenia. The extent of underuse in the United Kingdom compared to other European countries, and the extent of any regional variation within the UK remains unclear. Methods: We obtained data relating to all clozapine prescribing in the UK from the relevant clozapine registries. We compared the UK rate of clozapine use per 100,000 population to that described in other European countries. We also examined regional variation in clozapine use across England, corrected for the known prevalence of Severe Mental Illness (SMI). Findings: Clozapine prescribing rate in the UK was lower than in several European countries. Only a third of patients eligible for clozapine were prescribed the drug whilst there was substantial variation in prescribing across different regions of England. Interpretation: There is clear regional inequity in access to the most effective treatment in refractory schizophrenia. Strategies to increase clozapine use, by overcoming both real and perceived barriers, are urgently necessary to reduce treatment inequity for patients with refractory schizophrenia. Funding Statement: No funding was received for this project. Declaration of Interests: None. Ethics Approval Statement: The study was approved by the Drugs and Therapeutics Committee of the South London and Maudsley NHS Foundation Trust.