Study of antipsychotic use

Retrospective cross-sectional cohort study

Introduction

The National Institute for Health and Clinical Excellence (INESSS) has documented the use of antipsychotics among adults aged 25 or older, paying special attention to those aged 65 or older who have received a diagnosis of dementia.

Objectives

The aims of this study are to determine the prevalence and proportion of use of all types of antipsychotic therapies among adults aged 25 or older and to describe the use of antipsychotics by psychopathology group among those aged 65 or older, with a more detailed analysis of those diagnosed with dementia.

Methods

A retrospective cross-sectional descriptive study was carried out with individuals aged 25 or older who had ongoing coverage for at least 360 days during the years 2006 and 2009, under the Public Prescription Drug Insurance Plan administered by the Régie de l’assurance maladie du Québec (RAMQ).

Results

In 2009, in comparison to 2006, the prevalence of antipsychotic use increased 7.5 % among adults aged 25 or older. Short-term antipsychotic therapy experienced similar growth (10 %) in both age groups (25-64 year-olds and 65 or older), while the use of long-term combination therapy remained stable. As for long-term monotherapy, it increased twice as much (13.5 %) among 25-64 year-olds as it did among seniors (6.0 %).
Among seniors diagnosed with dementia, the prevalence of antipsychotic use increased by 13.3 % (from 1.5 % in 2006 to 1.7 % in 2009); risperidone was the most popular antipsychotic (46.7 % of all users), followed by quetiapine (37.7 % of cases).

Conclusion

Despite a lack of official indication as to the use of antipsychotics, specifically atypical (second-generation) antipsychotics, in geriatrics, these drugs are being prescribed in Québec to treat several psychopathologies. The prevalence of antipsychotic use among seniors diagnosed with dementia has also increased, despite the advisories issued by Health Canada to health care professionals concerning the increased risk of mortality and cerebrovascular events associated with the use of atypical (second-generation) antipsychotics. The long-term use of high doses and doses associated with a high risk of mortality observed among these patients, without this use being supported by clinical evidence, gives cause for concern and highlights the need to establish guidelines for antipsychotic use among seniors, especially those diagnosed with dementia.