The effects of cancer information exposure through mass media channels on clinical trial awareness and willingness to participate among Latinos/Hispanics: Results from the 2005 “Your Voice, Your Health Survey: Su Voz, Su Salaud ”

Sherrie Flynt Wallington, PhD Assistant Professor Georgetown University School of Medicine & Lombardi Comprehensive Cancer Center

Anne-Michelle Noone, MS Biostatistician Georgetown University School of Medicine & Lombardi Comprehensive Cancer Center

Gheorghe Luta, PhD Assistant Professor Georgetown University School of Medicine & Lombardi Comprehensive Cancer Center

Maria Lopez-Glass, Ph.D. Assistant Professor Georgetown University School of Medicine &  Lombardi Comprehensive Cancer Center

Vanessa Sheppard, PhD Assistant Professor Georgetown University School of Medicine & Lombardi Comprehensive Cancer Center

Larisa Caicedo, MA Director Nueva Vida, Incorporated

Cherie Spencer, MS XXXX Howard University Cancer Center

Elmer Huerta, MD, MPH XXXX Washington Cancer Institute and Washington Hospital Center

Jeanne Mandelblatt, MD, MPH  Professor Georgetown University School of Medicine & Lombardi Comprehensive Cancer Center

Address correspondence to:  Sherrie Flynt Wallington, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Research Building, W326A, 3970 Reservoir Rd, N.W., Washington, D.C. 20057; Telephone: 202-687-4378; fax: 202-687-6402; email: slw49@georgetown.edu.

This research was funded by a grant from the National Cancer Institute (U01 CA114593‐03S3) as part of the Latin American Cancer Research Coalition (LACRC).

Abstract

Objective:
This study examined the relationship between demographic and health variables, exposure to mass media channels, social-psychological variables, clinical trial awareness, and willingness to participate in clinical trials of Latinos/Hispanics.
Methods: We conducted a cross-sectional Spanish survey of 1351 Latino men and women > 21 years attending low-cost clinics. Logistic regression procedures were used to test whether demographic variables, media exposure variables, and social-psychological variables predicted clinical trial awareness and willingness to participate in a clinical trial
Results:
Married respondents (OR = 1.45, p = .03), respondents with 12 years of education (OR = 1.83, p = .001), respondents with more than 12 years of education (OR = 1.96, p = .001), use of Internet for health news and services (OR = 2.33, p = .001), likelihood of developing cancer (OR = -1.42, p = .03), and trust in health information from health sources (OR = 1.33, p = .001) predicted the probability of knowing what a clinical trial is. Calling the CIS (OR = 2.49, p = .05), attending health fairs (OR = 1.47, p = .03), worrying about developing cancer (OR = 1.91, p = .005), self-efficacy (OR = 1.14, p = .01), trust in health information from health sources (OR = 1.20, p = .03), and knowledge of a clinical trial (OR = 1.57, p = .003), predicted the probability of joining a clinical trial.
Limitations:
Measures of Internet use and likelihood of developing cancer were self-report. More objective measures of these variables would lead to more reliable results.
Conclusions: 
Demographic variables predicted knowledge of what a clinical trial was but did not predict willingness to participate in a clinical trial. Behavioral measures (i.e., calling the CIS, attending health fairs, and knowing what a clinical trial was) predicted willingness to participate in a clinical trial. Internet use predicted both outcome measures.

Key Words: Clinical trial awareness, clinical trial participation, Latinos/Hispanics, mass media

Introduction
It is well documented that despite the steady improvements in the overall health of Americans, some racial and ethnic minority populations, as well as members of lower socioeconomic groups, experience a lower quality of health services, are less likely to receive routine medical procedures, and have higher rates of morbidity and mortality than non-minorities and people of higher socioeconomic status (SES) 33. For example, even as the overall burden of cancer is steadily falling, the decline in both incidence and mortality varies for African-Americans, Hispanics/Latinos, American Indians, and Alaskan Natives compared to Whites 33. One possible reason for these disparities is the gap in translation of scientific knowledge and developments to all sectors of the public 76. This gap in translation of scientific knowledge and developments is further exacerbated by the lack of awareness of and participation in randomized clinical trials among racial and ethnic groups 2, 32, 79.
Many clinical trials have produced prevention and advancements in care for many diseases, including cancer. However, research shows that less than 5% of adult cancer patients enroll in clinical trials; in fact, only 3% of U.S. adults with cancer participate in clinical trials—far fewer than the number needed to address the most critical cancer issues quickly 50, 51, 79. Moreover, cancer clinical trial enrollment is much lower for minorities, the elderly, and underserved communities 5, 24, 61. This is particularly true for Latinos/Hispanics; even though they represent approximately 14.7% of the U.S. population and cancer is their second leading cause of death, they comprise only 3% of the cancer clinical trial population 4, 49, 70. A National Cancer Institute study 49 of clinical trials found that the number of trial enrollees relative to estimated U.S. cancer rates was significantly lower for Latinos/Hispanics and African-Americans as compared to Whites.
Among Latinos/Hispanics, this pattern has been particularly noted with low Latina participation rates in breast cancer trials, where Latina women account for less than 2% of participants 41, 43. These findings remain problematic and illustrate an urgent need to ameliorate low accrual rates among Latinos/Hispanics. If under-representation of Latinos/Hispanics in cancer clinical trials continues, it may in turn pose yet another constraint in access to care choices for this group, as clinical trials may be a viable and promising treatment option 49, 61. Another concern regarding Latinos’/Hispanics’ clinical trial under-representation is that it may also lead to an even greater paucity of data of this group’s response to certain scientific developments, for example, particular drug therapies 36. Minority groups’ response to certain drug regimens has become a rigorous scientific endeavor in pharmacogenomic studies as more definitive answers are sought to elucidate how certain persons and genetic subgroups respond to certain drug agents, as not all groups respond in the same manner 36, 80. Consequently, given that by 2050, Latinos/Hispanics will represent almost a quarter of the country’s population—98.2 million 70—and given that cancer is second only to cardiovascular disease as the leading cause of death among Latinos/Hispanics 4, it becomes imperative that Latinos/Hispanics participate in clinical trials to ensure generalizability of research results and to make certain that they benefit equitably from scientific knowledge and discovery 5, 15, 79.
To address this overwhelming concern of accrual of minorities in general to clinical trials, several research collaborations and educational and community-focused initiatives are now targeted toward improving this situation. For example, The National Institutes of Health (NIH) Revitalization Act of 1993 52 represents one important attempt to address under-representation and mandates that women and minorities must be recruited into trials to ensure valid conclusions on subpopulations. However, little is known from the patient perspective about factors that influence the decision to enroll in clinical trials 22. According to a Harris Interactive survey 29, most individuals with cancer who were surveyed were either unaware or unsure that participation in clinical trials was an option, and most of them also indicated that they would have been willing to enroll had they known it was possible. These findings represent important progress and opportunities in identifying barriers to Latino/Hispanic clinical trial participation, but more work needs to be done to better understand and improve strategies for accrual of Latinos/Hispanics in clinical trials.
To this end, researchers have called for a number of recommendations to address these barriers, and among these recommendations is the need for an investigation of effective communication strategies, including investigations on the best approaches to deliver information about clinical trials—both at the community level and at the point of interaction with the potential participant—and on the use of media-based and communication technology strategies. 24, 73. Some media-based interventions have been shown to be effective in increasing accrual to clinical trials 43, 69. Another study 12, focusing specifically on cancer prevention and Latina women, found that a media-based strategy utilizing English and Spanish newspaper advertisements was quite effective and suggested the media-based approach for the recruitment of other low-income groups to participate in clinical trials. Further, new communication technologies can facilitate access to a wealth of cancer information and health-related support services, thereby extending the reach of cancer communication efforts around clinical trials and delivering information to people at their preferred time and place, and in their desired format.
Technologies such as the Internet may conceivably enhance the health knowledge of consumers and thereby increase the awareness, enrollment, and participation of consumers in clinical trials, but they have not adequately reached socioeconomic groups at highest risk for poor health 7, 74, 77. Understanding communication and communication inequalities, particularly the role of the mass media and communication technologies in increasing clinical trial awareness and, ultimately, accrual of Latinos/Hispanics, is an understudied area and presents enormous opportunity to more effectively heighten awareness and increase trial recruitment, enrollment, and participation, and to serve as a foundation for future communication initiatives and strategies. We must pay attention to closing the gaps in clinical trial participation, particularly between the information “haves” and “have-nots,” and work to eliminate the knowledge gaps with Latinos/Hispanics regarding clinical trials 74.
To further help in elucidating these issues, this study uses, as a theoretical foundation, Tichenor, Donohue, & Olein’s (1970) 67 seminal knowledge gap hypothesis. The knowledge gap serves as a serviceable lens for assessing and emphasizing the social and structural influences to explain the differential exposure to media and the effect of this exposure at group—particularly different SES groups—and community levels 68,72. The knowledge gap hypothesis suggests that population segments with higher SES tend to acquire information from the media at a faster rate than do segments with a lower SES. Applied to cancer-related issues, these differences in information acquisition, or knowledge gaps, may lead to people’s inabilitaty to act on information related to prevention, screening, and treatment, thereby continuing to exacerbate cancer health disparities.
Hypotheses
Aims
In this current research, we used a subset of questions from the “Su Voz, Su Salud” (“Your Voice, Your Health”) survey to explore the relationship between demographic and health variables, exposure to mass media channels, social-psychological variables, clinical trial awareness, and willingness to participate in clinical trials of Latinos/Hispanics. We advanced the following hypotheses:
H1: Demographic variables (such as age, gender, marital status, and level of education) will predict clinical trial awareness and willingness to participate in clinical trials.
H2: The perceived likelihood of developing cancer will predict clinical trial awareness and willingness to participate in clinical trials.
H3: Type of media sources used will predict clinical trial awareness and willingness to participate in clinical trials.
H4: Internet use will predict clinical trial awareness and willingness to participate in clinical trials.
H5: Cell phone use will predict clinical trial awareness and willingness to participate in clinical trials.
H6: Acculturation will predict clinical trial awareness.
H7: Self-efficacy will predict clinical trial awareness.
H8: Trust in health information source will predict clinical trial awareness and willingness to participate in clinical trials.
H9: Knowledge about what a clinical trial is will predict willingness to participate in clinical trials.
Methods
 This study evaluated the information needs, information-seeking styles, and cancer knowledge of Latinos in the District of Columbia (DC) metropolitan area to fill key gaps in our knowledge about cancer information needs and communication styles of Central and South American Latinos. The study was conducted as part of the Latin American Cancer Research Coalition (LACRC). The LACRC is a National Cancer Institute-funded regional Community Network Program (CNP). The goal of the LACRC is to use community-based participatory research to promote cancer control in Latinos in the greater metropolitan DC region. The LACRC includes six community clinics, two community hospitals, one comprehensive cancer center, a local Spanish-language health radio program, a cancer support network, local universities, and numerous advocacy organizations. The LACRC community clinics serve Latinos almost exclusively and provide primary care regardless of ability to pay. All study procedures were approved by the Institutional Review Board.
Setting and Population
 A cross-sectional convenience, quota sample of individuals (n= ) attending the LACRC primary care sites between June 2007 and November 2008 were selected for participation. To evaluate the relationship between communication and screening behaviors and selected health behaviors, we stratified our sample by age and gender. In each of the nine sites, 25 participants were enrolled from each gender-age category: 21-29, 30-39, 40-54, and 55+. Participants were clinic users or individuals accompanying a registered patient, self-identified as Latinos, 21 years of age or older, and not enrolled in the Women Infants and Children (WIC) program. We also enrolled a convenience sample of Latinos attending health fairs sponsored by the LACRC clinics. We obtained informed consent (in Spanish) from all participants; each participant received a $10 gift card for his or her time.
Data Collection
Survey Development
 We developed a survey entitled “Your Voice, Your Health: Su Voz, Su Salud” using community participatory principles. We identified topics of interest to the LACRC community clinics and discussed the data that would be most useful to develop education campaigns and interventions to address the cancer control needs of their populations. We then used the National Cancer Institute (NCI) Health Information National Trends Survey (HINTS) to guide the selection of measures to conceptualize and measure the domains and topics identified by the partnership 53. We identified existing validated Spanish-language instruments, including items that had been successfully administered in the Spanish-language version of the HINTS survey 53.
Pre-Test
 We conducted a pre-test with a sample of 30 clinic users to test scale reliability. Any scales that were not reliable (Cronbach’s alpha < .6) were dropped or revised. Our final survey included sources of cancer information, factors that influence choice of medium, general cancer knowledge, family history, information-seeking styles, information self-efficacy, medical trust, acculturation, socio-demographics, and history of cancer screening.
Survey Administration
 Trained bicultural and bilingual cancer control coordinators conducted face-to-face interviews at our nine community clinic partner sites and health fairs. All interviews took place in a private location to maintain confidentiality; interviews lasted about 30 minutes. These interviews were conducted in the language of the participant’s choice. The interviewer used a laptop with the survey on screen to administer the survey and to record responses. If a participant was not comfortable with the computer, then the interviewer entered responses on a hard copy of the survey. XX% of surveys were completed using the laptop. The laptops were password protected. All data were transferred to one computer for analysis. Sites and participants were identified by number only.
Measures
Primary Outcomes  

The outcome variables for our analyses were clinical trial awareness and clinical trial participation. These items were assessed by two survey items with the following statements.
 Clinical trial awareness. Clinical trial awareness was assessed with the statement “Please tell me which one of the four definitions you think describes a clinical trial? Response options were “A project in a clinic, a test in an MD’s office, a research project in which some patients are selected to try new treatments medications while others receive different medications or none at all, a group of medical students, unsure (DO NOT READ), refused (DO NOT READ).”
 Clinical trial participation. Clinical trial participation was assessed (after explanation of a clinical trial) with the statement “In the future, if you developed a health problem like cancer, would you consider joining a clinical trial that was testing a new cancer treatment that could help you?”  Response options were “I would not participate, I might participate, I probably would participate, I definitely would participate, Not sure/haven’t thought about it, and Refused (DO NOT READ).”
Independent Variables
 Demographic. Standard demographic information was obtained from participants, including age, gender, marital status, and country of origin, and to test the knowledge gap hypothesis, we also included highest grade or level of schooling completed. To assess information-seeking behavior, participants were asked how often (not at all, very little, somewhat, quite a bit, always) they sought health information from the following sources: newspapers, magazines, radio, television, the Internet, health professionals (such as doctors and nurses), health educators/navigators, community leaders/priests, health fairs, and “Charlas de Salud” in the waiting room area at community clinics/church/community centers. Participants were also asked how much they trusted the information they received from these sources.
 Personal cancer risk. Two questions were asked that assessed participants’ perceptions of their personal cancer risk: (1) “In your opinion, how likely is it that you will develop cancer?” (hereafter referred to as “risk”), with possible responses ranging from “not at all likely” to “definitely” on a five-point scale; and (2) “In the past month, how often have you worried about your own chances of getting cancer?” (hereafter referred to as “worry”), with possible responses ranging from “not at all or rarely” to “a lot” on a four-point scale.
 Acculturation. Acculturation is always measured by proxy variables, which centrally include questions about an individual’s use of English versus his or her minority language in various settings 31. We measured acculturation by asking participants four questions about language preference: (1) “In general, what language(s) do you read and speak?” (2) “In which language do you think?” (3) “What language do you speak at home?” and (4) “What language do you speak with friends?” For each question, there were five possible responses: (1) only Spanish, (2) Spanish more than English, (3) both equally, (4) English more than Spanish, or (5) only English. The responses to these four questions were averaged to create an overall measure, with higher scores indicating higher levels of acculturation. Participants were also asked how many years they had lived in the United States, which was also used as an additional, separate measure of acculturation.
 Self-efficacy. An eight-question scale, modified from the Seeking and Understanding Medical Information Subscale from the Cancer Behavior Inventory, was used to measure self-efficacy 47. Participants were asked to choose a number between 1 and 9, where 1 represents “not at all confident” and 9 represents “totally confident” in response to phrases such as “How confident are you that you can: Ask nurses questions about cancer.” (See Appendix # for details.) Their responses to these questions were then averaged to create a composite score; individuals were given a score if they answered all eight items.  
Data Analysis
 We evaluated the associations between each outcome and study variables using t-tests and chi-square tests. We reviewed the functional form of the variables to determine whether a continuous score or categorical representation was most appropriate. The adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression for each outcome. Variable selection for each model was based on the significance (at 0.05 level) of univariate associations for that outcome; variables that were not significant at the 0.05 level were removed from the final model. Certain factors, however, such as age and acculturation remained in the final model even if not statistically significant.

Results
Descriptive Statistics
 The frequencies and percentages for the demographic and health variables are presented in Table 1. More than half of the respondents were from Central America (65%) and were married (66%). There was about an equal proportion of males and females. The majority of the respondents had 12 or fewer years of education (75%). Half of the respondents indicated that they were not likely to develop cancer (51%), while more than a third reported that they were likely to develop cancer (38%).
 The frequencies and percentages of the variables measuring media exposure are shown in Table 2. The primary source of health information for most of the respondents (66%) was their health care provider; this was followed by the media (27%). Slightly more than half of the respondents did not have access to the Internet (59%). Most of the respondents, however, had a cell phone (77%).
 The means and standard deviations for the variables measured continuously are presented in Table 3. The mean age of the sample was 41 (SD = 13). The theoretical range for self-efficacy was 1 through 9; higher scores indicated higher self-efficacy. The mean self-efficacy score was 6.7 (SD = 1.6). The theoretical range for acculturation was 1 through 5; higher scores reflected greater acculturation. The mean acculturation score was 1.5 (SD = .7). The theoretical range for trust in health information source was 1 through; higher scores indicated greater trust. The mean trust score was 4 (SD = .9).
Predictors of Knowledge about What a Clinical Trial Is
 Demographic variables. The independent t-test findings indicate that age did not significantly predict knowledge about what a clinical trial is (p = .25; Table 6). The cross-tabulation results assessing the relationship between the demographic variables and knowledge about what a clinical trial is are shown in Table 4. The findings indicate that region, marital status, level of education, and likelihood of developing cancer significantly predicted knowledge about what a clinical trial is. Respondents from South America had better knowledge than their counterparts in North and Central America (p = .03). Married respondents had better knowledge than unmarried respondents (p = .004). More educated respondents had better knowledge than respondents who had less than 12 years of education (p = .001). Respondents who had a low likelihood of developing cancer had better knowledge than those who had a high likelihood of developing cancer (p = .005).
 Media exposure variables. The cross-tabulation results assessing the relationship between the media exposure variables and knowledge about what a clinical trial is are summarized in Table 5. The findings reveal that primary source of health information and use of the Internet significantly predicted knowledge about what a clinical trial is. Respondents who received health information from the media and other sources had better knowledge than respondents who received health information from their health care provider and significant people in their lives (p = .001). Respondents who used the Internet for health searches had better knowledge than respondents who did not have Internet access and respondents who did not use the Internet to do health searches (p = .001).
 Social-psychological variables. The means, standard deviations, and p-values for the social-psychological variables are displayed in Table 6. Acculturation and trust in health information from health sources were significantly associated with knowledge about what a clinical trial is. Respondents who knew what a clinical trial was had significantly higher mean acculturation scores (M = 1.6, SD = .7) than respondents who did not know what a clinical trial was (M = 1.4, SD = .6; p = .001). Respondents who knew what a clinical trial was also had higher trust scores (M = 4.2, SD = .9) than those who did not know what a clinical trial was (M = 3.9, SD = 1.0; p = .001).
 Multivariable model for the probability of knowing what a clinical trial is. The multivariable logistic regression findings are summarized in Table 7. The findings reveal that marital status, level of education, Internet use for health searches, likelihood of developing cancer, and trust in health information from health sources were associated with having knowledge of clinical trials. After controlling for all other characteristics, married respondents (OR = 1.45, p = .03) had greater odds of knowing what a clinical trial was than unmarried respondents. Respondents with 12 years of education (OR = 1.83, p = .001) and respondents with more than 12 years of education (OR = 1.96, p = .001) had greater odds of knowing what a clinical trial was than respondents with less than 12 years of education. Respondents who used the Internet to search for health news and services (OR = 2.33, p = .001) had greater odds of knowing what a clinical trial was than those who did not use the Internet. Respondents who indicated they were not likely to develop cancer (OR = 1.42, p = .03) had greater odds of knowing what a clinical trial was than respondents who indicated they were likely to develop cancer. The greater the trust in health information from health sources, the greater the odds that respondents would know what a clinical trial was (OR = 1.33, p = .001).
Predictors of Joining a Clinical Trial
 Demographic variables. The independent t-test results indicate that age did not significantly predict joining a clinical trial (p = .55; Table 10). The cross-tabulation results assessing the relationship between the demographic variables and joining a clinical trial are shown in Table 8. The findings indicate that none of the demographic variables significantly predicted joining a clinical trial, but worry about developing cancer significantly predicted joining a clinical trial. Respondents who often worried about developing cancer in the past month indicated that they were probably or definitely joining a clinical trial more than respondents who sometimes worried or did not worry about developing cancer (p = .001).
 Media exposure variables. The cross-tabulation results assessing the relationship between the media exposure variables and joining a clinical trial are summarized in Table 9. The findings indicate that calling the Cancer Information Line (CIS) and going to health fairs were significantly associated with the likelihood of joining a clinical trial. A greater percentage of respondents who had called the CIS reported that they were more likely to join a clinical trial in contrast to respondents who had never called the CIS (p = .01). A greater percentage of respondents who had attended health fairs indicated that they were more likely to join a clinical trial than respondents who did not attend health fairs (p = .01).
 Social-psychological variables. The means, standard deviations, and p-values for the social-psychological variables are displayed in Table 10. Self-efficacy and trust in health information from health sources significantly predicted joining a clinical trial. Respondents who indicated that they would probably/definitely join a clinical trial had higher self-efficacy scores (M = 6.9, SD = 1.5) than respondents who indicated that they would not/might join a clinical trial (M = 6.5, SD = 1.5; p = .001). Respondents who indicated that they would probably/definitely join a clinical trial also had higher trust scores (M = 4.1, SD = .9) than respondents who indicated that they would not/might join a clinical trial (M = 3.9, SD = 1.0; p = .02).
 Multivariable model for the probability of joining a clinical trial. The multivariable logistic regression findings are summarized in Table 11. The findings reveal that calling the CIS, attending health fairs, worry about developing cancer, knowledge of a clinical trial, self-efficacy, and trust in health information from health sources predicted the probability of joining a clinical trial. Respondents who had called the CIS (OR = 2.49, p = .05) had greater odds of joining a clinical trial than respondents who had not called the CIS. Respondents who had attended health fairs (OR = 1.47, p = .03) had greater odds of joining a clinical trial than respondents who had not attended health fairs. Respondents who worried about getting cancer often/a lot (OR = 1.91, p = .005) had greater odds of joining a clinical trial than respondents who did not worry at all. Respondents who knew what a clinical trial was (OR = 1.57, p = .003) had greater odds of joining a clinical trial than those who did not know. The higher the self-efficacy score, the greater the odds that respondents would join a clinical trial (OR = 1.14, p = .01). The greater the trust in health information from health sources, the greater the odds that respondents would join a clinical trial (OR = 1.20, p = .03).

Discussion
Clinical trial knowledge may not be evenly distributed throughout the population, thereby exacerbating knowledge gaps and communication inequalities about clinical trials, fostering low participation rates, and perpetuating cancer health disparities. This present study highlights the importance of closing existing clinical trial knowledge gaps and low participation rates among Latinos/Hispanics. Mass media are an important source of learning about population health 72 topics, including clinical trials.42, 69 We used data from the 2005 “Your Voice, Your Health Survey: Su Voz, Su Salaud” to test the premise that cancer information exposure through mass media channels is associated with clinical trials awareness and clinical trial participation among Latinos/Hispanics.
 Clinical Trial Awareness. We expected that demographic variables such as age, gender, marital status, and level of education would be associated with clinical trial awareness. We found that being married and educated (12 years or greater) were significantly associated with knowledge about what a clinical trial is. Age and gender were not significant. Compared to other studies, findings related to demographic variables are mixed.  In one non-Latino/Hispanic
study 37 that investigated cancer patients’ awareness of clinical trials, researchers found marital status was not related to clinical trial awareness. In a more recent study13, researchers found that race, ethnicity, income, education, and family history of cancer significantly and uniquely predicted whether or not participants had heard of clinical trials. Too, the fact that more educated Latinos/Hispanics had more knowledge about clinical trials than less educated Latinos/Hispanics suggests that it is necessary to take into account socioeconomic status variation within racial and ethnic groups rather than mask them by treating them as one monolithic group 76.
We also anticipated that perceived likelihood of developing cancer would predict clinical trial awareness. With respect to cancer, an individual’s perceived cancer risk (PCR) predicts his/her likelihood of engaging in preventive health behaviors 35, 71. We found that those with a lower perceived likelihood of developing cancer surprisingly had better knowledge of what a clinical trial was than those who had a higher perceived likelihood of developing cancer. It seems more plausible that having a low PCR would contribute to less attentiveness to clinical trial communication through mass media, and thus less knowledge awareness of what a clinical trial is. The significance of low PCR and better knowledge about clinical trials is unclear and warrants further research. Some recent work 54 suggests that, in general, low PCR among Latinos/Hispanics and other minority groups may be a result of people less able to report their family history of cancer, cancer risk salience—people basing their cancer risk perceptions on the experiences and beliefs of their same race or ethnic group or social network—and whether PCR even represents a meaningful concept for a given group. Thus, low PCR may then be a barrier among Latinos/Hispanics to screening and other cancer prevention behaviors and even awareness of and participation in clinical trials.
Our findings also support the notion that media have been ascribed a great deal of power in influencing both individual and population health 74. The belief in the media’s power to influence individual and population health stems in part from the immense amount of time people spend with the media 72. We found that media attention, even more so than receipt of health information from respondents’ health care provider or significant people in their lives, plays a significant role in becoming aware of clinical trials. Specifically, Internet usage was positively related to better clinical trial knowledge.
In general, recent research has begun to show promising results around the use of the Internet and Web-based strategies in cancer clinical trial education and recruitment.20, 45, 48 However, more effort is needed to equalize Internet usage patterns among Latinos/Hispanics with other groups, as research is beginning to show promising results around the use of the Internet and Web-based strategies in cancer clinical trial education and recruitment.20, 45, 48 The Pew Hispanic Center and Pew Internet Project56 report that although Latinos/Hispanics comprise approximately 14% of the U.S. adult population, only about half of this growing group (56%) goes online. By comparison, 71% of non-Hispanic Whites and 60% of non-Hispanic Blacks use the Internet. Our finding represents a growing shift away from the stark and earlier digital divide issues —the perceived gap between those who have access to the latest information technology and those who don’t 19.
We also found that acculturation (based on language) was significantly associated with knowledge about what a clinical trial is. Acculturation has become a popular construct in research on health disparities among ethnic minorities and presumes that individuals choose or reject behaviors based on their cultural beliefs and that such choices are prime factors affecting their health 31. Although little is known about how acculturation affects clinical trial awareness and participation, increasing acculturation among Latinos/Hispanics has been shown to influence knowledge, attitudes, and behaviors related to such issues as cancer genetic test awareness, mammography adherence, and utilization of cervical cancer screening 28, 66, 64.
Trust in health information gained from a variety of sources is an important driver of information seeking, which may lead to in increased health knowledge and positive health behaviors 57. We found that trust in health information from health sources was significantly associated with knowledge about what a clinical trial is. This finding may be supported by the fact that many Latino/Hispanic groups may receive their health care from clinics that predominately serve Latinos/Hispanics and have bilingual administrative and medical staff, and consequently, they experience less discrimination and have a higher satisfaction with patient-provider relationships 63. Moreover, the value of having a Latino/Hispanic health provider for achieving patient-physician cultural concordance 34 may in turn lead to greater trust and better health discussions, including discussions about clinical trials.
Clinical Trial Participation. We expected that our socio-demographic variables would be associated with willingness to participate in clinical trials. However, in contrast to our expectations, the findings show that none of our socio-demographic variables were associated with joining a clinical trial. Brown and Moyer (2010)13 suggest that motivations and disincentatives for potential research participants may differ by socio-demographic factors and particularly by race and ethnicity. For example, among Latinos/Hispanics, factors associated with under-representation in cancer clinical trials are multi-factorial 6. Such factors include a particular emphasis regarding obstacles of socio-cultural beliefs about health care, diminished social resources, learned helplessness, economic disparity, language barriers, educational differentials, lack of provider cultural competency, lack of perceived value and involvement in clinical trials of Latino/Hispanic physicians, and poor community readiness to promote trial participation 22, 40, 9, 58.
Compared with other groups, higher levels of education and positive beliefs about the medical risks of research predicted willingness to participate among Whites 62. Among Blacks, awareness of the infamous Tuskegee Syphilis Study (in which poor Black men were denied treatment for syphilis from 1932-1972 26 has been heavily cited as the singular reason behind their clinical trial under-representation and mistrust of medical and health providers.11, 27 However, Brandon, Isaac, and LaViest10 suggest the Tuskegee legacy plays less of a significant role in engendering distrust among Black and other minority groups and point to other multiple and complex factors. These factors include lack of physicians/providers’ awareness and referrals to clinical trials,  personal mistreatment by health and medical establishments,  perceived costs or lack of health insurance,  geographic and personal constraints (e.g., child care, inflexible work hours, transportation), language and health literacy concerns, lack of minority investigators in the trial research design and implementation, lack of family or peer support, inclusion and exclusion eligibility criteria, and unavailability of an appropriate trial represent some of the well-documented complex factors contributing to poor trial participation rates among minority groups.1, 16, 18, 22, 25, 30, 59, 79  In spite of these barriers, more research is providing evidence that, when asked to participate in clinical trials, Latinos/Hispanics and other minority groups, are willing to do so and enroll at the same rates as non-Hispanic Whites 17, 40, 79.
We also expected that our media types, particularly the Internet, would predict willingness to participate in clinical trials. The Internet and other media types were not associated with clinical trial participation, but the National Cancer Institute’s Cancer Information Service (CIS and attending health fairs were significantly associated with likelihood of joining a clinical trial. Related to CIS, due to NCI’s special efforts to promote the CIS, particularly among minority and underserved populations, many Latinos/Hispanics and other minority groups appear to be more aware of this service 65. Established in 1975 and with some recent changes, the CIS exists to help the public obtain the latest, most accurate scientifically vetted information about cancer prevention behaviors and practices, screening recommendations and procedures, and the most recent advances in cancer treatment 65. In one CIS study, Squiers et al. 65 found that although overall awareness of CIS was low (32%), interestingly, African-Americans and Latinos/Hispanics were significantly more aware of the CIS than Whites, thus possibly contributing to increased clinical trial awareness and participation. More research is needed to see if Latino/Hispanics CIS awareness necessarily equates with actual CIS usage. In addition, health fairs are ideal venues for community outreach and have been shown to be quite effective in promoting the prevention of and screening for various cancers. 14
In summary, some interesting highlights of our findings reveal that demographics predicted knowledge about what a clinical trial is but did not predict the likelihood of joining a clinical trial. Likewise, use of Internet predicted knowledge but did not predict joining. In contrast, self-efficacy predicted joining but not knowledge. Moreover, factors that predicted willingness to participate entailed more “involvement” and efficacy on the part of respondents. For instance, calling the CIS meant being more involved, attending health fairs meant being more involved, knowing what a clinical trial is meant being more involved.
 Limitations. We note some limitations of the current study. Due to the cross sectional nature of this study, none of the variables were controlled and manipulated, thus, causality could not be established. Further, we can only generalize to the areas where respondents were recruited from. Finally, more objective measures of perceived risk of cancer and likelihood of having cancer are needed as these measures were self report.
 Strengths. Cross-sectional studies make valuable research contributions insofar as they set the stage for subsequent hypothesis-driven research questions 78. Therefore, an important strength of this study involves our ability to help develop priorities for future work regarding increasing clinical trial awareness and participation among Latinos/Hispanics. Also, this study is unique in its in-depth assessment of communication and mass media constructs specifically among Latinos/Hispanics as it relates to clinical trial awareness and participation.
 Conclusions. The challenge of minority accrual in clinical trials is well recognized, and recruiting and retaining Latinos/Hispanics poses even greater complexities 3, 21, 44. Given that Latinos/Hispanics represent one of the fastest growing ethnic populations and have poor cancer outcomes, it is critical that they be aware and participate in clinical trials to ensure generalizability of cancer research results and to make certain that they benefit equitably from cancer scientific knowledge and discovery. These efforts will not only help to ameliorate low participation rates but will also assist with the important goal of reducing and eliminating cancer health disparities among Latinos/Hispanics.  While our study raises some intriguing questions for future research related to clinical trial awareness and participation, it also gives us some important insights related to health communication and use of various mass media channels. Among Latinos/Hispanics, there is a critical need to provide, through multiple channels (i.e., patient-physician encounters, mass media, and community encounters such as health fairs and other community forums), targeted (group) and tailored (individual) 39 information to increase clinical trial awareness and participation.

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