Effects of Social Determinants of Health on Physical Health Outcomes: A Comparison Between Vietnamese Refugees and Immigrants in the United States

Background and Purpose: Despite the presence of over one million foreign-born Vietnamese in the US, the individual and public health implications of social determinants of health (SDH) have not been sufficiently addressed among Vietnamese Americans. Given the lack of recognition of heterogeneity within the Vietnamese community, few research has explored within-group differences between Vietnamese refugees and immigrants. Although primarily viewed as refugees, there are Vietnamese immigrants who are exposed to differing pre- and post-migration experiences. Using the SDH framework, this study examines: 1) various SDH factors associated with physical health outcomes among Vietnamese Americans; and 2) how these associations differ by migration status (i.e., refugee vs. immigrants).

Methods: We conducted a secondary data analysis using a subset of foreign-born Vietnamese refugees (n=289) and immigrants (n=209) in the National Latino and Asian American Study (NLAAS). The NLAAS contains a nationally representative sample of non-institutionalized Asian adults older than 18 years. Based on the SDH framework, we examined structural factors (everyday discrimination & neighborhood environment); material factors (poverty status, employment status, & insurance status), and psychosocial factors (physical and psychological traumas), along with sociodemographic factors (age, sex, education, limited English proficiency (LEP), and age at immigration). We conducted linear and Poisson regression analyses to examine associations between the SDH factors and two health outcomes: self-rated physical health (SRPH) and Chronic Medical Conditions (CMC), respectively. All analyses were weighted to take into account multi-stage probability sample selection and to correctly estimate standard errors.

Results: Weighted descriptive analyses showed that, compared with their immigrant counterparts, Vietnamese refugees reported higher level of SRPH and CMC; were older with more years of education; reported better neighborhood environment; were insured at a higher rate; and experienced higher levels of physical and psychological traumas. The linear regression results showed that, among Vietnamese immigrants, being female (b=-0.39, p<.05), LEP (b=-0.33, p<.05) and being poor (b=-0.44, p<.05) were significantly associated with lower SRPH. Among Vietnamese refugees, LEP (b=-0.50, p<.01), everyday discrimination (b=-0.28, p<.05), being poor (b=-0.59, p<.01), and being unemployed (b=-0.46, p<.05) were significantly associated with lower SRPH. The Poisson regression results revealed that, for Vietnamese immigrants, being female (IRR=1.71, 95% CI [1.15-2.55]), more education (IRR=1.04, [1.01-1.08]), being poor (IRR=1.27, [1.03-1.58]), being insured (IRR=1.43, [1.03-1.98]), and physical trauma (IRR=1.23, [1.05-1.44]) were associated with greater likelihood of having CMC.  For refugees, older age (IRR=1.02, [1.01-1.04]), age at immigration (IRR=0.99, [0.97-1.00]), everyday discrimination (IRR=1.18, [1.01-1.39]), being poor (IRR=1.35, [1.03-1.77]), being unemployed (IRR=1.30, [1.00-1.69]), being insured (IRR=1.59, [1.05-2.41]), physical (IRR=1.17, [1.05-1.31]), and psychological (IRR=1.14, [1.06-1.22]) trauma experiences were associated with increased likelihood of having CMC.

Conclusion and Implication: The findings suggest that the SDH provides a framework for examining the effects of trauma and migration status on physical health outcomes for Vietnamese refugees and immigrants. In addition to the physical and psychological trauma they have experienced before and after the migration, everyday discrimination appeared to influence refugees’ physical health long after their resettlement. These findings warrant further research on the impacts of pre- and post-migration traumatic experiences among different groups of Vietnamese Americans.