Understanding Differences in Prescription Drug Use Between Mexican Americans and Non-Hispanic White Americans: Results from the National Health and Nutrition Examination Survey (NHANES)

Background: Several studies have found that Mexican Americans are less likely than Non-Hispanic White Americans to use prescription drugs; however, the factors underlying this association remain unclear. We sought to evaluate the factors mediating the association between race/ethnicity and prescription drug use. We also investigated this association among persons with various health conditions to better understand differences in potential for unmet need. Methods: The exposure of interest was race/ethnicity, comparing Mexican Americans to Non-Hispanic White Americans. The outcome was prescription drug usage within the past 30 days (yes vs no). Several variables were assessed as potential mediators. The percentage mediated and its respective 95% CI was calculated using bootstrapping with 1000 repetitions. Significant mediators were included in a joint difference mediation model that was analyzed using multinomial logistic regression. We also looked at those with diabetes, hypertension, hyperlipidemia, or depression. Logistic regression models were used to calculate odds ratios (unadjusted and fully adjusted) and their 95% CIs for the association between race/ethnicity and use of a prescription drug class corresponding to the condition. Results: Non-Hispanic whites were more likely to have taken prescription drugs in the past 30 days than Mexican Americans (67.2% vs 37.5%). The joint mediation model mediated 44.3% of the relationship between race/ethnicity and prescription drug use. Among those with diabetes, Mexican Americans were more likely to be treated with an antidiabetic. Among those with hypertension, hyperlipidemia, or depression, Mexican Americans were less likely to be treated than Non-Hispanic whites, with hypertension and depression having statistically significant unadjusted and fully adjusted models. Conclusions: The association between race/ethnicity and prescription drug use is partially mediated by age, poverty income ratio, and variables reflecting health access. Disparities in prescription drug use persist among those with hypertension and depression. Further investigations should be done to better understand this disparity and the underlying factors contributing to it.Bachelor of Science in Public Healt