Health Literacy As a Social Determinant of Health in Asian American Immigrants: Findings from Population-Based Survey in California

Background/Purpose: Immigrant populations are considered to be some of the groups most vulnerable to health disparities in the United States. One of the major contributors to these disparities is health literacy. Combined with linguistic and cultural barriers, health literacy is a critical determinant of immigrant health, as it provides individuals with motivation and ability to best understand and use information to promote their health conditions. Although Asian American immigrants as a whole may have a lower level of health literacy than non-Latino Whites, little is known about different levels of health literacy among distinct ethnic groups in Asian immigrants. To our knowledge, no study has explored how health literacy, across different subgroups of Asian immigrant populations, has an impact on different health outcomes. Our objectives in this study are to identify: (1) the levels of health literacy among five subgroups of Asian immigrants, when compared to the aggregated Asian immigrant group and non-Latino Whites; and (2) the impact of health literacy on two health outcomes, self-rated health status and depressive symptoms, across these five subgroups of Asian immigrants, when controlling for all relevant covariates.

Methods: We used a cross-sectional survey research design and a population-based sampling strategy using the 2007 California Health Interview Survey (CHIS). We sampled 30,615 non-Latino Whites and 3,053 Asian American immigrants (1,058 Chinese, 598 Koreans, 534 Filipinos, 416 South Asians, and 447 Vietnamese). We assessed the level of health literacy of non-Latino whites, and both aggregated and disaggregated Asian American immigrants. We then investigated the effect of health literacy on two main health outcomes: self-rated health status and depressive symptoms. We used SPSS 20.0 for all analyses.

Results: The level of health literacy varied across five subgroups of Asian American immigrants. On average, the mean score of health literacy in non-Latino whites was significantly higher than that of the aggregated Asian immigrant group (p<0.001). However, health literacy fluctuated across different subgroups of Asian immigrants when disaggregated. For example, only Chinese, Korean, and Vietnamese groups had significantly lower levels of health literacy than that of non-Latino whites, with the Filipino group reporting the highest level of health literacy, even higher than that of non-Latino whites, although the difference was not statistically significant.

Findings from multiple regression models revealed that Asian immigrants with a higher level of health literacy would have a higher level of self-rated health status and a lower level of depressive symptoms than their counterparts. Health literacy was significantly correlated with self-rated health status and depressive symptoms for Chinese, Korean, and South Asian immigrants.

Conclusion: We found heterogeneity in health literacy among Asian American immigrants and that health literacy had varying impacts on health outcomes. The aggregated Asian American immigrant group may mask the true health disparities that each Asian American immigrant group faces. Koreans appear to be the most disadvantaged group experiencing health disparity as a result of inadequate health literacy. Further research is needed to better understand the causes of heterogeneity and to explain health literacy as a critical determinant of immigrant health.