Prescription drug expenditures of immigrants in the USA

Abstract

Given the substantial growth rate of the immigrant population, it is critical to examine immigrants' prescription drug expenditure patterns to encourage medication adherence. The aim was to examine and compare prescription drug expenditures and out-of-pocket (OOP) payment by respondents' US citizenship/nativity status and years spent in the USA, and identify factors associated with these expenditure differences. This study examined total prescription drug expenditures and the proportion of OOP payment to the total drug expenditures for US-born citizens, naturalized US citizens (≤10 and >10 years of US residence) and non-US citizens (≤10 and >10 years of US residence) aged 18–64 years. Two-part multivariate models were used to estimate the effect of citizenship/nativity status and years in the USA on drug expenditures and OOP shares. The Blinder–Oaxaca decomposition techniques were used to identify the most important factors associated with these disparities. Non-US citizens and naturalized US citizens had lower drug expenditures and higher OOP shares than US-born citizens, and these disparities decreased with more years of US residence. Decomposition results showed that approximately 80% of the disparities in total drug expenditures could be explained by the observed population characteristics. The major variables associated with these disparities were indicators for cultural background, English proficiency, immigrants' self-selections and educational attainment, followed by healthcare access and insurance. Approximately 75% of the differences in OOP shares could be explained by the observed characteristics. Inadequate health insurance coverage and limited healthcare access were major factors associated with these disparities. The results suggested that immigrants' higher drug OOP shares could be reduced by improving their health insurance coverage and access. However, to reduce the disparities in total drug expenditures, providing English-assistance and culturally designed programmes to the immigrants would be more effective than improving their healthcare access directly.