New Method Enables Comparison of Antipsychotic Use in Adults with Intellectual Disability Across UK Services
Introduction
A recent study has introduced a novel approach to evaluate and compare antipsychotic medication use among adults with intellectual disability (PwID) receiving specialist care in England and Wales. This method involves converting various antipsychotic doses into chlorpromazine-equivalent units, allowing clearer assessment of prescribing practices across different services.
Key Findings
The retrospective cohort study analyzed anonymized data from 424 adults with intellectual disability who were prescribed two or more antipsychotic medications between 2017 and 2023. Data were collected from eight specialist adult intellectual disability services across England and Wales.
Researchers successfully converted antipsychotic doses to chlorpromazine equivalents for 98% of cases, enabling standardized comparisons. They found that individuals diagnosed with psychosis, behaviours that challenge, depression, or attention-deficit/hyperactivity disorder tended to receive significantly higher chlorpromazine-equivalent doses.
Notably, over 25% of the cohort were prescribed doses exceeding 1000 mg/day chlorpromazine equivalent, surpassing the maximum dose recommended by the British National Formulary.
Context and Importance
Antipsychotics are commonly prescribed to people with intellectual disabilities for both licensed indications such as psychosis and unlicensed uses like managing challenging behaviours. However, before this study, there was no standardized system to compare prescribing patterns across specialist services, making it difficult to monitor and improve medication practices.
Implications for Families and Care Providers
This chlorpromazine-equivalent conversion method offers a straightforward tool for healthcare providers to assess antipsychotic burden and align prescribing with best practice guidelines. For families and carers, it may lead to more transparent medication reviews and safer prescribing decisions.
Limitations and Considerations
While the approach facilitates comparison, the study was based on retrospective data and convenience sampling, which may limit generalizability. Also, higher doses do not necessarily indicate inappropriate prescribing, as individual clinical needs vary. Further research is needed to explore outcomes related to different dosing levels.
Conclusion
Converting antipsychotic doses to chlorpromazine equivalents appears to be an effective strategy to evaluate and compare prescribing practices in adults with intellectual disability. This method could support efforts to optimize medication use and enhance patient safety across specialist services.
For more detailed information, see the original study published in the Journal of Psychopharmacology: A novel approach for evaluating and comparing multiple antipsychotic polypharmacy in adults across specialist intellectual disability services in England and Wales.
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