Estimating ethnic differences in self-reported new use of antidepressant medications: results from the Multi-Ethnic Study of Atherosclerosis.

Introduction: There is evidence that the utilization of antidepressant medications (ADM) may vary between different ethnic groups in the United States population.

Methods: The Multi-Ethnic Study of Atherosclerosis (MESA) is a population-based prospective cohort study of 6814 US adults from 4 different ethnic groups. After excluding baseline users of ADM, we examined the relation between baseline depression and new use of ADM for 4 different ethnicities: African-Americans (n = 1822), Asians (n = 784) Caucasians (n = 2300), and Hispanics (n = 1405). Estimates of the association of ethnicity and ADM use were adjusted for age, study site, gender, Center for Epidemiologic Studies Depression Scale (CES-D), alcohol use, smoking, blood pressure, diabetes, education, and exercise. Non-random loss to follow-up was present and estimates were adjusted using inverse probability of censoring weighting (IPCW).

Results: Of the four ethnicities, Caucasian participants had the highest rate of ADM use (12%) compared with African-American (4%), Asian (2%), and Hispanic (6%) participants. After adjustment, non-Caucasian ethnicity was associated with reduced ADM use: African-American (HR: 0.42; 95% Confidence Interval (CI): 0.31-0.58), Asian (HR: 0.14; 95%CI: 0.08-0.26), and Hispanic (HR: 0.47; 95%CI: 0.31-0.65). Applying IPCW to correct for non-random loss to follow-up among the study participants weakened but did not eliminate these associations: African-American (HR: 0.48; 95%CI: 0.30-0.57), Asian (HR: 0.23; 95%CI: 0.13-0.37), and Hispanic (HR: 0.58; 95%CI: 0.47-0.67).

Conclusion: Non-Caucasian ethnicity is associated with lower rates of new ADM use. After IPCW adjustment, the observed ethnicity differences in ADM use are smaller although still statistically significant.