L. Cindy Chang

Understanding Suboptimal Human Papillomavirus Vaccine Uptake Among Ethnic Minority Girls

Background: The introduction of human papillomavirus (HPV) vaccines represents a breakthrough in the primary prevention of cervical cancer. However, little is known about vaccination uptake and correlates among low-income, ethnic minority, and immigrant populations in the U.S. who may benefit most from the vaccine. Methods: Telephone interviews (N = 490) were conducted in six languages between January and November 2009 among mothers of vaccine-eligible girls (ages 9–18) using the Los Angeles County Department of Public Health, Office of Womens Health service referral hotline. HPV and vaccine awareness, knowledge, beliefs, barriers, and daughters vaccine receipt were assessed. Results: The sample consisted of low-income, uninsured, ethnic minority, and immigrant women. Only 29% of daughters initiated the vaccine and 11% received all three doses. No ethnic differences were observed in initiation or completion rates. Ethnic differences were observed in HPV awareness, perceived risk, and other vaccine-related beliefs. The strongest predictor of initiation was vaccine awareness (OR = 12.00). Daughters age and reporting a younger acceptable age for vaccination were positively associated with initiation. Mothers of unvaccinated girls reported lacking information about the vaccine to make a decision (66%) and not knowing where they could obtain the vaccine (74%). Conclusion: Vaccination rates in this sample were lower than state and national estimates, and were associated with low levels of vaccine awareness. Interventions, including culturally targeted messaging, may be helpful for enhancing HPV–vaccine knowledge, modifying vaccine-related beliefs and increasing uptake. Impact: Our findings provide valuable guidance for developing interventions to address suboptimal HPV vaccination in high-risk groups. Cancer Epidemiol Biomarkers Prev; 20(7); 1463–72. ©2011 AACR.

Results of a randomized trial to increase mammogram usage among Samoan women

Background: There are no effective breast cancer education programs targeting Samoan women. We tested the effectiveness of a theory-guided, culturally appropriate breast cancer education program (the intervention) designed to increase mammography use among Samoan women. Methods: This community-based participatory cluster-randomized controlled intervention trial used a parallel two-group design. The sample consisted of 776 women aged 42 and older who had not had a mammogram in the preceding 2 years. The primary outcome was self-reported mammogram use between pretest and posttest. Results: Overall, there was no statistically significant intervention effect, although the odds of self-reported mammogram use were higher in the intervention than the control group (odds ratio (OR), 1.26; 95% confidence interval (95% CI), 0.74, 2.14; P = 0.39). Exploratory subgroup analyses found that the intervention was effective only among women who were aware of mammograms but had never previously obtained one (OR, 1.99; 95% CI, 1.03, 3.85; P = 0.04). Low need for social support and lack of endorsement of culture-specific beliefs about breast cancer were associated with mammogram use in this group. In women unaware of mammography at pretest, high perceived susceptibility to breast cancer and endorsement of culture-specific beliefs were associated with mammogram use. For women who had previously obtained a mammogram, lower self-efficacy was associated with mammogram use. Intervention compared with control group women had significantly higher levels of knowledge of risk factors and lower endorsement of culture-specific beliefs at posttest. Conclusions: Results suggest that a multifaceted education intervention may improve mammogram usage for certain subgroups of Samoan women. (Cancer Epidemiol Biomarkers Prev 2007;16(12):2594–604)

Validation of Self-reported Colorectal Cancer (CRC) Screening in a Study of Ethnically Diverse First-Degree Relatives of CRC Cases

Background: Evidence about the accuracy of self-reports of colorectal cancer (CRC) screening is lacking. We conducted a validation protocol in a randomized trial to increase CRC screening among high-risk individuals. Methods: First-degree relatives (n = 1,280) of CRC cases who were due for CRC screening were included in the parent trial. All subjects who completed the follow-up interview (n = 948) were asked to participate in validation activities. Self-reports of receipt of CRC screening during the 12-month study period were verified via physicians. Results: Although 60% (n = 567) verbally agreed, only 171 subjects (18% of original sample) returned the signed validation form with the physician name and contact information and a medical information release statement. The signed forms were mailed to physicians with a

Changes in risk perceptions in relation to self-reported colorectal cancer screening among first-degree relatives of colorectal cancer cases enrolled in a randomized trial.

10 incentive and the request to list the dates of recent CRC screening tests. One hundred twenty-three physicians (72% of physicians contacted, 13% of original sample) returned completed validation forms. Rates of agreement were low across all three screening types with physicians verifying self-reported screening for 29% of fecal occult blood testing, 56% of sigmoidoscopy, 55% of colonoscopy, and 57% of any screening test. Conclusion: Validation of self-report using the type of protocol we used for subjects receiving medical care in many community settings may be unfeasible and cost inefficient. Given the overall low participation rate in validation activities and considerable challenges in collecting high quality data, conclusions about the accuracy of self-reported CRC screening are difficult to make based on the results of this study. (Cancer Epidemiol Biomarkers Prev 2008;17(4):791–8)

Cluster-randomized trial to increase hepatitis B testing among Koreans in Los Angeles

OBJECTIVE This secondary data analysis was conducted to evaluate the applicability of the Risk Reappraisal Hypothesis, which has been proposed to explain the influence of performing a health behavior on perceived risk. Data were collected in the context of a randomized trial, which found that an individually tailored, multicomponent intervention was successful in increasing colorectal cancer (CRC) screening among first-degree relatives of CRC cases. METHOD The ethnically diverse study sample (N = 841; 29% Latino, 21% African American, 20% Asian) consisted of adult siblings and children (40-80 years) of CRC cases, identified through the California Cancer Registry. Data were collected at baseline and at 6- and 12-month follow-up. Changes in self-reported risk perception (perceived likelihood of developing CRC) were examined over the study period in relation to study condition and screening status. RESULTS Greater increases in perceived risk were observed among intervention versus control-group participants over the study period, but increases were limited to intervention participants who had not been screened. We also examined trajectories of perceived risk in relation to timing of screening receipt (e.g., before 6 months, 6-12 months, never). Continued upward shifts in risk were observed during the study period among intervention participants not screened during the study. In contrast, participants screened by 6 months displayed a reduction or leveling off in perceived risk between 6- and 12-month follow-up. CONCLUSION Results provide support for the applicability of the Risk Reappraisal Hypothesis within a high-risk sample enrolled in a CRC screening promotion trial. Future research is needed to explore the impact of short-term risk reductions on future CRC screening behavior.

Theoretically Informed Correlates of Hepatitis B Knowledge among Four Asian Groups: The Health Behavior Framework

Background: In the United States, Korean immigrants experience a disproportionately high burden of chronic hepatitis B (HBV) viral infection and associated liver cancer compared with the general population. However, despite clear clinical guidelines, HBV serologic testing among Koreans remains persistently suboptimal. Methods: We conducted a cluster-randomized trial to evaluate a church-based small group intervention to improve HBV testing among Koreans in Los Angeles. Fifty-two Korean churches, stratified by size (small, medium, large) and location (Koreatown versus other), were randomized to intervention or control conditions. Intervention church participants attended a single-session small-group discussion on liver cancer and HBV testing, and control church participants attended a similar session on physical activity and nutrition. Outcome data consisted of self-reported HBV testing obtained via 6-month telephone follow-up interviews. Results: We recruited 1,123 individuals, 18 to 64 years of age, across the 52 churches. Ninety-two percent of the sample attended the assigned intervention session and 86% completed the 6-month follow-up. Sample characteristics included were as follows: mean age 46 years, 65% female, 97% born in Korea, 69% completed some college, and 43% insured. In an intent-to-treat analysis, the intervention produced a statistically significant effect (OR = 4.9, P < 0.001), with 19% of intervention and 6% of control group participants reporting a HBV test. Conclusion: Our intervention was successful in achieving a large and robust effect in a population at high risk of HBV infection and sequelae. Impact: The intervention was fairly resource efficient and thus has high potential for replication in other high-risk Asian groups. Cancer Epidemiol Biomarkers Prev; 24(9); 1341–9. ©2015 AACR.

An Experimental Test of the Effect of Incentives on Recruitment of Ethnically Diverse Colorectal Cancer Cases and Their First-Degree Relatives into a Research Study

BACKGROUND Few studies have examined theoretically informed constructs related to hepatitis B (HBV) testing, and comparisons across studies are challenging due to lack of uniformity in constructs assessed. The present analysis examined relationships among Health Behavior Framework factors across four Asian American groups to advance the development of theory-based interventions for HBV testing in at-risk populations. METHODS Data were collected from 2007-2010 as part of baseline surveys during four intervention trials promoting HBV testing among Vietnamese-, Hmong-, Korean- and Cambodian-Americans (n = 1,735). Health Behavior Framework constructs assessed included: awareness of HBV, knowledge of transmission routes, perceived susceptibility, perceived severity, doctor recommendation, stigma of HBV infection, and perceived efficacy of testing. Within each group we assessed associations between our intermediate outcome of knowledge of HBV transmission and other constructs, to assess the concurrent validity of our model and instruments. RESULTS While the absolute levels for Health Behavior Framework factors varied across groups, relationships between knowledge and other factors were generally consistent. This suggests similarities rather than differences with respect to posited drivers of HBV-related behavior. DISCUSSION Our findings indicate that Health Behavior Framework constructs are applicable to diverse ethnic groups and provide preliminary evidence for the construct validity of the Health Behavior Framework.

Factors associated with HPV awareness among mothers of low-income ethnic minority adolescent girls in Los Angeles

Background: Optimizing participant response rates is important for obtaining representative samples and the timely completion of studies. It is a common practice to use participant incentives to boost response rates, but few studies have systematically examined their effectiveness, particularly among minority groups. Methods: We experimentally tested three incentive strategies for their effectiveness in improving response rates among colorectal cancer cases (n = 3,816) and their relatives (n = 2,353). A 2 × 2 × 2 factorial design compared (a) registered versus first class mail, (b)

Prostate cancer screening among ethnically diverse first-degree relatives of prostate cancer cases

5 cash with the initial mailing (yes/no), and (c)

Randomized trial to increase colorectal cancer screening in an ethnically diverse sample of first-degree relatives

20 promise (yes/no) upon completion of the information form (for cases) or