Place of birth, cancer beliefs and being current with colon cancer screening among US adults

Introduction

Approximately four decades ago, studies suggested that Japanese immigrants acquired the risk of colorectal cancer (CRC) as Caucasians in Hawaii within the same generation [1]. This was before the advent of widespread CRC screening in the United States. Access and utilization of screening are known to affect CRC burden [2]. Factors associated with low uptake of CRC screening include low socioeconomic status, lack of or inadequate insurance coverage, low literacy level, and low perceived cancer risk [3-5]. Using data from the 1998 National Health Interview Survey (NHIS), Goel et al [6] reported a non-significant reduced odds of prior fecal occult blood testing (FOBT) and sigmoidoscopy use among foreign- versus US-born respondents. This was in the pre-colonoscopy screening era and colonoscopy is fast becoming the dominant CRC screening modality in the United States [7,8].

Beliefs about the cause of a particular disease can influence whether and how an individual takes steps to reduce the risk of developing that disease [9]. Powe reported that fatalism (attitude of perceiving everything as being ordained by fate) was associated with lower uptake of FOBT among 192 study participants [10]. In the present study we evaluated the association of place of birth (US- versus foreign-born) and cancer beliefs with being current with CRC screening guidelines using FOBT, sigmoidoscopy and colonoscopy.

Materials and methods

Results US-born respondents were older, mean age 64.0 years (95%CI: 63.8-64.2) compared to mean age 61.4 years (95%CI: 60.1-62.6) of foreign-born respondents. The mean age using weighted survey analysis for continuous variables does not produce P value. Rather, it produces mean age and the 95% CI. There is a notable difference in the mean age as evidenced by lack of overlap of the 95% CI. However, the “unweighted analysis” would have been: P=0.0035 using non-parametric rank-sum test. US-born respondents were more likely to be non-Hispanic whites (P<0.001), had more formal education (P<0.001), more likely to have health insurance (P<0.001) and were more likely to have a history of smoking (P=0.0013). There was no difference in sex preponderance (Table 1). Being foreign-born was associated with a 35% statistically significant reduced odds of being current with CRC screening in the univariate analysis but the effect became attenuated after adjustments for potential confounders (OR 0.79; 95%CI: 0.5 -1.24) (Table 2).

Table 1 Comparison of the characteristics of respondents by place of birth

Table 2 Univariate and multivariate analysis of association between place of birth and being up-to-date with colorectal cancer screening

Our findings suggest that the opinion of respondents regarding cancer, influence their being current with CRC screening guidelines. Respondents who had a favorable opinion that cancer can be detected early and cured were more likely to be current, whereas those with fatalistic beliefs were less likely to be current with CRC screening guidelines (Table 3).

Table 3 Association between cancer beliefs and being up-to-date with colorectal cancer screening

Discussion

We evaluated the association of place of birth (US- versus foreign-born) with being current with CRC screening guidelines. We found important differences by nativity in factors known to affect CRC screening. For example, there was a higher representation of Hispanics, lower formal education and higher percentage of respondents without health insurance coverage among foreign-born persons. Nonetheless, after taking these factors into consideration, our study is suggestive that in general, foreign-born adults in the US have lower uptake of CRC screening. We also evaluated the effect of cancer beliefs with compliance with CRC screening guidelines. We found that respondents who have positive opinion about cancer prevention were more likely to be current with CRC screening. The lower screening rates among foreign-born respondents may be related to a relative lack of organized or programmatic population based CRC screening in their countries of origin. Although HINTS did not collect data to ascertain the country of origin of foreign-born respondents, whether they migrated as adults or not and the time that has elapsed since migration, we speculate that foreign-born persons were probably less aware of CRC screening which may also be related to their poorer access to healthcare services. Overall, our study underscores the need for increased education of the population about CRC prevention, particularly among foreign-born persons.

Our findings corroborate a previous report by Goel et al [6]. In that study, the authors used data from the 1998 National Health Interview Survey and reported that foreign-born persons were less likely to be up-to-date with CRC screening with FOBT and sigmoidoscopy. This was prior to widespread use of colonoscopy as a screening modality. In recent times, colonoscopy is fast becoming the dominant screening modality with reduced use of other acceptable methods of CRC screening [7,8]. However, in our study, we evaluated the use of FOBT, sigmoidoscopy and colonoscopy and our findings are similar.

A low perceived risk of CRC which may be due to lack of knowledge about family history of CRC [12] in combination with inadequate knowledge of the efficacy of CRC screening has been reported to be associated with a reduced uptake of CRC screening [2,3]. Fatalism has been reported to be a psychological and sociocultural barrier and has been associated with lower uptake of FOBT screening [10]. In contrast, uptake of CRC screening is higher among US-born respondents and among those who believe that CRC screening is efficacious. This aligns with the health belief model which suggests that people are apt to act when they believe they are susceptible to the condition (perceived susceptibility), believe the condition has serious consequences (perceived severity), believe taking action would reduce their susceptibility to the condition or its severity (perceived benefits), believe costs of taking action (perceived barriers) are outweighed by the benefits, are exposed to factors that prompt action (e.g. a television advertisement or a reminder from one’s physician), and are confident in their ability to successfully perform an action (self-efficacy) [13]. Therefore, regularly providing information about advances in cancer prevention and management will be important in reducing cancer fatalistic beliefs and thus improve CRC screening uptake among US adults. Immigrants should be encouraged to discuss their diagnosis with members of their family so that they may become more aware of their individual risk so that persons at higher risk of this deadly, but largely preventable disease can take important steps to mitigate their risks. A culturally sensitive approach tailored to foreign-born individuals may also increase their acceptance and subsequent participation in CRC screening.

There are some notable strengths of our study. We used a large, nationally representative sample of US adults. The 2007 iteration of HINTS was conducted in English and Spanish with two communication modalities (telephone and mail), thereby ensuring a broad reach of the population. However, our study is limited by the fact that it was based on self-report and there was no medical record review to validate CRC screening. There was relatively small number of foreign-born persons. Percentage of foreign-born in our study is 9%, while the actual percentage of foreign-born in the US is 13% [14]. Overall response rate of HINTS 2007 was modest; 24% for the random digital dial sample and 31% for mail sample. Furthermore, there was no information on the regions of the world foreign-born respondents migrated from to the United States.

In conclusion, suboptimal uptake of CRC screening may contribute to increased risk of CRC among immigrants in this modern era of widespread CRC screening. It is important for healthcare providers to inquire about cancer beliefs of all patients to inform cancer prevention education intervention and counseling.