Our study suggests that foreign birth explains some differences in cancer screening previously attributed to race and ethnicity. In our initial analyses, we found that Hispanic and AAPI persons were significantly less likely to receive many forms of cancer screening than white persons, despite adjustments for sociodemographic factors and illness burden. After accounting for birthplace, we found that U.S.-born Hispanic and AAPI persons were generally as likely to report screening as U.S.-born whites, but that foreign-born Hispanic and AAPI persons were significantly less likely to report many forms of cancer screening, suggesting that previous differences attributed to race and ethnicity were driven largely by birthplace. Access to health care appears to explain some, but not all of the observed differences in screening between foreign-born and U.S.-born persons. In particular, the influence of access to health care was more pronounced among foreign-born Hispanic persons than foreign-born AAPI persons.
Consistent with prior studies, our initial analyses confirm that Hispanic and AAPI persons living in the United States are less likely to report cancer screening. These racial and ethnic disparities were previously attributed to differences in factors such as income, education, geographic residence, and health care access.7–10,22–27
In our study, adjusting for access to care attenuated differences in screening by race and ethnicity, but socioeconomic factors such as education and income did not play a major role.
Our analyses examining the influence of birthplace also confirm prior studies which show that racial/ethnic subgroups comprised largely of immigrants have lower screening rates for cervical, breast, and colorectal cancer.2–7
One hypothesis for this screening disparity may be that foreign-born persons are disproportionately affected by barriers such as lower income, less education, and lack of access to care. While some demographic and socioeconomic barriers are more prevalent among foreign-born persons, our study demonstrates differences by birthplace persisted even after accounting for factors such as education and income. In addition, while adjusting for access to care substantially attenuated differences between foreign-born and U.S.-born Hispanic persons, it did not explain the large difference between foreign-born and U.S.-born AAPI persons.
Previous studies suggest that immigrants may experience unique barriers to care.2–11,17,18,23,24,28–30
Language and cultural differences between immigrants and health care providers may lead to poorer communication about the importance of cancer screening, and result in lower screening rates.9,15–18
Additional barriers may include provider characteristics such as gender and ethnicity, as seen in studies demonstrating that AAPI women cared for by female or non-AAPI physicians have higher rates of cervical and breast cancer screening.8,9,23
Whether these factors are important among non-AAPI immigrant groups is unclear. Acculturation factors such as number of years in the United States and cultural preferences associated with country of origin may influence cancer screening and are deserving of further study.
Clarifying the relationship between race, ethnicity, and foreign birth is important because it may help identify specific barriers faced by these at-risk populations, and can create opportunities to intervene and improve health. Cancer screening leads to earlier identification and treatment of disease, and ultimately to lower mortality.28–33
Some data suggest that immigrants present at more advanced stages of disease and have poorer survival because of advanced stage at presentation.6,34–36
Therefore, identifying specific areas of intervention may ultimately lead to improved morbidity and mortality.
Based on our findings, one of the barriers disproportionately affecting foreign-born persons, especially foreign-born Hispanics, is poor access to health care. Improving access by providing health insurance coverage, encouraging the identification of a primary care provider, and teaching the benefits of annual well visits may increase screening. Access to care, however, may only be one of many factors affecting cancer screening.
The observation that for AAPI persons the disparity in cervical cancer screening is not accounted for by access to care suggests that there may be additional cultural barriers to care that require exploration. Further research should focus on factors that may be specific to immigrants, such as the influence of limited English proficiency and poor access to culturally competent health care providers. Additionally, general factors that may have unique effects on immigrants deserve study, such as lack of knowledge about the benefits of cancer screening, the effects of provider gender and race/ethnicity, amount of time spent with patients, frequency with which cancer screening is offered, and subsequent patient responses to screening recommendations. Potential interventions include improving interpreter services, reducing geographic barriers (such as distance, accessibility by public transportation, etc.), and targeting health care providers to educate their immigrant patients about the benefits of cancer screening and repeatedly offer screenings.
Although we utilized a nationally generalizable population, our study has limitations. First, the National Health Interview Survey (NHIS) relies exclusively on patient-reported information, which may lead to recall bias. We attempted to minimize recall bias by choosing the most lenient cancer screening criteria recommended, and adjusting for educational differences. Another limitation was potentially increased nonresponse from non-English, non-Spanish speakers. We were unable to identify which respondents used translators or the respondent's language proficiency, and therefore could not adjust for this variable. Additionally, these procedures may have resulted in an increased nonresponse from households where no family members spoke English or Spanish. This nonresponse would likely bias our findings toward the null, thus underestimating the relationship between cancer screening and foreign birth found in our study. Immigrants are a heterogeneous population with different levels of acculturation, which were not measured directly in this survey. In the future, we would like to explore this further when improved information about the number of years in the United States and language proficiency becomes available. It is possible that acculturation patterns may affect screening patterns differently in different ethnic subgroups. We did not have adequate sample sizes to pursue additional analyses in the majority of Hispanic and Asian ethnic subgroups.
In summary, foreign birth may be a barrier to some forms of cancer screening, and may explain some disparities previously attributed to race or ethnicity. Although improving access to care may attenuate some of the differences observed between foreign-born and U.S.-born persons, particularly among foreign-born Hispanic persons, additional research is needed to explore causal factors for differences in cancer screening, especially for foreign-born AAPI persons. In the interim, foreign-born persons should be targeted for improved health care access and appropriate cancer screening.