Ethnic differences in the use of prescription drugs: a cross-sectional analysis of linked survey and administrative data

BACKGROUND Evidence from the United States and Europe suggests that the use of prescription drugs may vary by ethnicity. In Canada, ethnic disparities in prescription drug use have not been as well documented as disparities in the use of medical and hospital care. We conducted a cross-sectional analysis of survey and administrative data to examine needs-adjusted rates of prescription drug use by people of different ethnic groups. METHODS For 19 370 non-Aboriginal people living in urban areas of British Columbia, we linked data on self-identified ethnicity from the Canadian Community Health Survey with administrative data describing all filled prescriptions and use of medical services in 2005. We used sex-stratified multivariable logistic regression analysis to measure differences in the likelihood of filling prescriptions by drug class (antihypertensives, oral antibiotics, antidepressants, statins, respiratory drugs and nonsteroidal anti-inflammatory drugs [NSAIDs]). Models were adjusted for age, general health status, treatment-specific health status, socio-economic factors and recent immigration (within 10 years). RESULTS We found evidence of significant needs-adjusted variation in prescription drug use by ethnicity. Compared with women and men who identified themselves as white, those who were South Asian or of mixed ethnicity were almost as likely to fill prescriptions for most types of medicines studied; moreover, South Asian men were more likely than white men to fill prescriptions for antibiotics and NSAIDs. The clearest pattern of use emerged among Chinese participants: Chinese women were significantly less likely to fill prescriptions for antihypertensives, antibiotics, antidepressants and respiratory drugs, and Chinese men for antidepressant drugs and statins. INTERPRETATION We found some disparities in prescription drug use in the study population according to ethnic group. The nature of some of these variations suggest that ethnic differences in beliefs about pharmaceuticals may generate differences in prescription drug use; other variations suggest that there may be clinically important disparities in treatment use.