Ethnic Disparities in Antipsychotic Drug Use in British Columbia: A cross-sectional retrospective study

Authors: 
Joseph H. Puyat, Gillian E. Hanley, Colleen M. Cunningham, Michael R. Law, Sabrina T. Wong, Jason M. Sutherland, Steven G. Morgan
Research Summary: 


Objective
This study examined ethnic disparities in antipsychotic therapy in a population with significant Asian representation.

Methods
Using a cross-sectional retrospective study design, self-reported ethnicity data pooled from three cycles of the Canadian Community Health Survey were linked to 2005 administrative data on physician, hospital, and pharmaceutical use in British Columbia, Canada. Logistic regression was used to model the association between ethnicity and the likelihood of filling one or more prescriptions for any antipsychotic, with controls for sex, age, residence, immigrant status, income, health status, and diagnoses of schizophrenia, bipolar disorder, depression, and dementia.

Results
Of the 27,658 individuals in the sample, 2.2% filled at least one antipsychotic prescription. The proportion varied across ethnic groups: Chinese, 1.0%; other Asians, 1.2%; whites, 2.3%; nonwhite non-Asians, 2.8%; and mixed ethnicity, 4.3%. After adjustment for patient characteristics and diagnoses of schizophrenia and bipolar disorder, the likelihood of filling a prescription was found to be lower among Chinese (odds ratio [OR]=.47, 95% confidence interval [CI]=.24–.90) and higher among persons of mixed ethnicity (OR=3.19, CI=1.49–6.83). Further adjustment for depression and dementia diagnoses did not significantly change the ORs for the Chinese (OR=.49, CI=.25–.98) and the mixed ethnic groups (OR=2.97, CI=1.30–6.80).

Conclusions
Consistent with the existing literature on ethnic disparities in antipsychotic therapy, the study found evidence of persistent disparities in a population that has a significant number of Asians. Further studies should be done to identify possible causes of these disparities and to identify potential interventions that may reduce or eliminate them.