摘要：Objectives . The author examined the prevalence and predictors of colorectal cancer screening among the urban Japanese population of the United States. Methods . A sample of Japanese residents of major US metropolitan areas completed a self-administered mailed survey. Results . Physician recommendation, acculturation, and perceived psychological costs were consistent predictors of screening for colorectal cancer. Gender and marital status were related to screening via fecal occult blood testing; age, susceptibility, and health insurance were related to sigmoidoscopy/colonoscopy screening. Conclusions . Colorectal cancer screening among the urban Japanese population could be increased with interventions seeking to promote physician recommendations for screening, alleviate perceived psychological costs among patients, and improve physician–patient communication. How should disease prevention strategies be organized in a heterogeneous society in which disease incidence rates vary among different groups? How are factors associated with screening among specific ethnic groups in the United States different from those among the broader population identified in the literature? In this article, I examine these questions with respect to colorectal cancer (CRC) and CRC screening among Japanese Americans. The incidence of CRC among Japanese Americans exceeds the rate among nonHispanic Whites 1 ; US Japanese men rank after only Alaska Native men in terms of age-adjusted race- and gender-specific CRC incidence rates, and US Japanese women rank third, after Alaska Native and African American women. 2 CRC rates have also increased in Japan, which now has an incidence equivalent to that of the United States. 3, 4 Several epidemiological studies suggest that the higher genetic predisposition to CRC among the US Japanese population—through, for example, the fast acetylator genotype coupled with Western dietary patterns, including a diet high in red meat—may explain in part the increased CRC incidence rates in Japanese immigrants and their descendants. 5, 6 There is growing evidence linking other factors such as socioeconomic status (SES) and screening access to the differing rates of CRC among multiethnic US populations, 7– 9 but the mechanism by which different factors interact to increase risk is unknown. Stage at diagnosis is one of the most important prognostic factors for CRC survival; administering appropriate screening tests is important for improved cancer outcomes. 1 Despite the elevated CRC incidence among Japanese Americans, no published information is available regarding CRC screening behavior in this group, which now represents 0.3% of the US population. 10 Results gathered from the 1997 Behavioral Risk Factor Surveillance System (BRFSS) 11 questionnaire indicated that Asian American/Pacific Islanders (AAPIs) 50 years and older were half as likely as non-Hispanic White respondents to have had a fecal occult blood test (FOBT) during the preceding year (11.5% vs 20.1%). Similarly, after adjustment for SES and other health care indicators, a multiethnic population study showed underuse of CRC screening among AAPIs aged 50 to 64 years. 12 Lee-Feldstein et al 13 examined factors related to CRC mortality in a group of 1329 multiethnic Medicare patients from a single geographic area and found that AAPIs experienced significantly greater CRC mortality than did White patients after adjustment for stage at diagnosis, tumor location, hospital type, type of health insurance, and sociodemographic indicators. These authors did not discuss differences in genetic predisposition to CRC or rates of CRC screening among AAPIs, and thus unmeasured cultural attributes may have contributed to the increased risks observed. Few cross-sectional studies 14– 17 have attempted to disentangle the underlying attributes accounting for differences in CRC screening rates among certain Asian subgroups, but some have indicated that greater acculturation, increased physician recommendation, and higher SES are significantly associated with increased screening rates. However, results are difficult to interpret because these studies have relied on different measures of acculturation and CRC screening behavior. Given the great diversity within AAPI communities with respect to historical, cultural, linguistic, and socioeconomic characteristics, 18 it is unknown whether these findings can be generalized to Japanese Americans. Furthermore, the fact that CRC incidence rates among Japanese men and women between the ages of 30 and 54 years have been shown to be 18% and 42% higher, respectively, than rates among US non-Hispanic White men and women 1 in the same age group suggests that health education and community outreach efforts should be extended to younger age groups. Andersen’s model of health care utilization 19, 20 has been widely used to identify priority areas of intervention for improving the use of CRC screening. For example, some studies have examined the effects of health insurance or urban/rural residence on detection of CRC and linked lack of insurance or rural area of residence to late-stage diagnosis. 21, 22 Andersen included measures of individual health risks as well as a range of other measures that influence health behavior 23– 26 and grouped these factors into 3 categories: predisposing, enabling, and need related. In some of the cross-sectional studies 27– 29 explicitly applying Andersen’s model, the pattern of results has been consistent: health insurance coverage, urban/rural residence, regular access to care, and availability of medical providers appear to be important predictors of various cancer screening behaviors and access to primary care. Whether investigated in isolation or as part of a behavioral theory (i.e., the Health Belief Model [HBM] 30 or other models of behavioral change), some health beliefs, such as perceived susceptibility to CRC and perceived barriers to CRC screening, have shown consistent correlations with CRC screening participation or intention. 31– 37 The same is true of physician recommendations to undergo screening. In this study, I drew on Andersen’s model to evaluate associations between probable correlates of screening and CRC screening participation among US Japanese residents 30 years and older.
