Vickie L. Shavers

Racial Differences in Factors that Influence the Willingness to Participate in Medical Research Studies

PURPOSE The relative absence of racial/ethnic minorities among medical research subjects is receiving considerable attention because of recent government mandates for their inclusion in all human subject research. We examined racial differences in the prevalence of sociocultural barriers as a possible explanation for the underrepresentation of African Americans in medical research studies. METHODS During 1998-1999, a total of 198 residents of the Detroit Primary Metropolitan Statistical Area (PMSA) participated in a survey that examined impediments to participation in medical research studies. Chi square tests and logistic regression analyses were used to examine the association between race, issues related to trust of medical researchers, and the willingness to participate in medical research studies. RESULTS Study results indicate that African Americans and whites differ in their willingness to participate in medical research. Racial differences in the willingness to participate in a medical research are primarily due to the lower level of trust of medical research among African Americans. African American respondents were also somewhat less willing to participate if they attribute high importance to the race of the doctor when seeking routine medical care, believed that minorities bear most of the risks of medical research, and if their knowledge of the Tuskegee Study resulted in less trust in medical researchers. CONCLUSION These data reiterate the need for medical researchers to build trusting relationships with minority communities. Researchers can begin by acknowledging the previous medical abuse of minority research participants, discussing their specific plans to assure the protection of study participants, and explaining the need for the participation of racial/ethnic minorities including studies that specifically target or that are likely to result in disproportionate representation of racial/ethnic minorities among study participants.

Lung cancer risk and red meat consumption among Iowa women

OBJECTIVE Some epidemiologic studies suggest that diets high in total fat, saturated fat, or cholesterol are associated with increased risk of lung cancer. Others suggest that diets high in red meat consumption, particularly well-done red meat, are a lung cancer risk factor. In Iowa, we had the opportunity to investigate concurrently the role of meat intake and macronutrients in lung cancer etiology. METHODS A population-based case-control study of both non-smoking and smoking women was conducted in Iowa. A 70-item food frequency questionnaire (FFQ) was completed by 360 cases and 574 frequency-matched controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression. Multivariate models included age, education, pack-years of smoking, yellow-green vegetable intake, fruit/fruit juice intake, nutrient density calories, previous non-malignant lung disease, alcohol consumption and body mass index (BMI). RESULTS When comparing the fifth (highest) to the first (lowest) quintile of consumption of total fat, saturated fat and cholesterol, we obtained odds ratios of 2.0 (1.3-3.1), 3.0 (1.9-4.7), and 2.0 (1.3-3.0) respectively. However, when red meat was entered into the model along with total fat, saturated fat or cholesterol, the excess risk for the macronutrients disappeared while an odds ratio of 3.3 (1.7-7.6) was obtained for red meat. The odds ratios for red meat consumption were similar among adenocarcinoma cases, OR=3.0 (1.1-7.9) and non-adenocarcinoma cases, OR=3.2 (1.3-8.3) and among life-time nonsmokers and ex-smokers OR=2.8 (1.4-5.4), and current smokers, OR=4.9 (1.1-22.3). Yellow-green vegetables were protective with an odds ratio of 0.4 (0.2-0.7). CONCLUSIONS Consumption of red meat, was associated with an increased risk of lung cancer even after controlling for total fat, saturated fat, cholesterol, fruit, yellow-green vegetable consumption and smoking history, while yellow-green vegetables are associated with a decreased risk of lung cancer.

Racial/Ethnic Patterns of Uptake of Colorectal Screening, National Health Interview Survey 2000-2008

BACKGROUND Lower access and/or utilization of colorectal screening are thought to be major contributors to the higher proportion of cancers among African Americans and Hispanics that are diagnosed at advanced stages of disease and the poorer outcomes observed among Hispanics and African Americans compared with non-Hispanic whites. We examine rates of initiation, utilization of specific screening modalities, adherence tocolorectal screening guidelines, and rate of uptake of colonoscopy among age-eligible African Americans, Hispanics and non-Hispanic whites. METHODS Data on 46145 African American, Hispanic, and non-Hispanic white survey respondents to the 2000 and 2005 Cancer Control Modules and the 2003 and 2008 Sample Adult Cores of the National Health Interview Surveys are examined in these analyses. RESULTS There was a modest increase in the initiation of colorectal screening among non-Hispanic whites, only and racial/ethnic disparities colorectal screening utilization persisted. The proportion of respondents for whom colonoscopy was the most complete guideline consistent exam received increased over time, while use of other modalities decreased among all racial/ethnic groups. CONCLUSION More effort must be made to increase colorectal screening among the U.S. population in general but particularly among racial/ethnic minority populations. With the increased attention on prevention, there is also a need to increase knowledge of the strengths and limitations of specific screening modalities and the need to receive screening exams within recommended time intervals among both patients and providers making screening recommendations.