Recruitment of immigrant and ethnic minorities in primary prevention trials of cardiovascular disease

Recruitment, retention and reporting of variables related to ethnic diversity in randomised controlled trials: an umbrella review

OBJECTIVE

This umbrella review synthesises evidence on the methods used to recruit and retain ethnically diverse participants and report and analyse variables related to ethnic diversity in randomised controlled trials.

DESIGN

Umbrella review.

DATA SOURCES

Ovid MEDLINE, Ovid Embase, CINAHL, PsycINFO and Cochrane and Campbell Libraries for review papers published between 1 January 2010 and 13 May 2024.

ELIGIBILITY CRITERIA

English language systematic reviews focusing on inclusion and reporting of ethnicity variables. Methodological quality was assessed using the AMSTAR 2 tool.

RESULTS

Sixty-two systematic reviews were included. Findings point to limited representation and reporting of ethnic diversity in trials. Recruitment strategies commonly reported by the reviews were community engagement, advertisement, face-to-face recruitment, cultural targeting, clinical referral, community presentation, use of technology, incentives and research partnership with communities. Retention strategies highlighted by the reviews included frequent follow-ups on participants to check how they are doing in the study, provision of incentives, use of tailored approaches and culturally appropriate interventions. The findings point to a limited focus on the analysis of variables relevant to ethnic diversity in trials even when they are reported in trials.

CONCLUSION

Significant improvements are required in enhancing the recruitment and retention of ethnically diverse participants in trials as well as analysis and reporting of variables relating to diversity in clinical trials.

PROSPERO REGISTRATION NUMBER

CRD42022325241.

Reducing racial and ethnic disparities in cardiovascular outcomes among cancer survivors

PURPOSE OF REVIEW

Analyze current evidence on racial/ethnic disparities in cardiovascular outcomes among cancer survivors, identifying factors and proposing measures to address health inequities.

RECENT FINDINGS

Existing literature indicates that the Black population experiences worse cardiovascular outcomes following the diagnosis of both initial primary cancer and second primary cancer, with a notably higher prevalence of cardio-toxic events, particularly among breast cancer survivors. Contributing socioeconomic factors to these disparities include unfavorable social determinants of health, inadequate insurance coverage, and structural racism within the healthcare system. Additionally, proinflammatory epigenetic modification is hypothesized to be a contributing genetic variation factor. Addressing these disparities requires a multiperspective approach, encompassing efforts to address racial disparities and social determinants of health within the healthcare system, refine healthcare policies and access, and integrate historically stigmatized racial groups into clinical research. Racial and ethnic disparities persist in cardiovascular outcomes among cancer survivors, driven by multifactorial causes, predominantly associated with social determinants of health. Addressing these healthcare inequities is imperative, and timely efforts must be implemented to narrow the existing gap effectively.

Representation of Racial and Ethnic Minorities in Nephrology Clinical Trials: A Systematic Review and Meta-Analysis

SIGNIFICANCE STATEMENT

Racial and ethnic disparities in clinical trial enrollment are well described. However, whether these disparities are present in nephrology randomized clinical trials has not been previously reported. We performed a systematic review and meta-analysis of 380 randomized clinical trials involving different aspects of kidney disease published between 2000 and 2021. Our results indicate that worldwide reporting of race and ethnicity is poor and that White individuals account for most of the randomized participants with decreased enrollment of Black participants in more recent trials. However, trials conducted in the United States have representation of Black and Hispanic participants consistent with the population prevalence of disease and under-representation of Asian participants.

BACKGROUND

Under-representation of racial and ethnic minorities in clinical trials could worsen disparities, but reporting and enrollment practices in nephrology randomized clinical trials have not been described.

METHODS

PubMed was searched to capture randomized clinical trials for five kidney disease-related conditions published between 2000 and 2021 in ten high-impact journals. We excluded trials with <50 participants and pilot trials. Outcomes of interest were the proportion of trials reporting race and ethnicity and the proportions of enrolled participants in each race and ethnicity category.

RESULTS

Among 380 trials worldwide, race was reported in just over half and ethnicity in 12%. Most enrolled participants were White, and Black individuals accounted for ≤10% of participants except in dialysis trials where they accounted for 26% of participants. However, Black participants were enrolled at high proportions relative to disease and population prevalence in US CKD, dialysis, and transplant trials representing 19% of participants in AKI, 26% in CKD, 44% in GN, 40% in dialysis, and 26% in transplant trials. Enrollment of Asian participants was low worldwide except in GN trials with marked under-representation in US CKD, dialysis, and transplant trials. Hispanic individuals represented only 13% of participants in US dialysis trials compared with 29% of US dialysis population.

CONCLUSION

More complete reporting of race and ethnicity in nephrology trials is needed. Black and Hispanic patients are well-represented in kidney disease trials in the United States. Asian patients are poorly represented in kidney trials both globally and in the United States.

Inequity in care delivery in cardio-oncology: dissecting disparities in underrepresented populations

It is well known that patients with cancer have a significantly higher cardiovascular mortality risk than the general population. Cardio-oncology has emerged to focus on these issues including risk reduction, detection, monitoring, and treatment of cardiovascular disease or complications in patients with cancer. The rapid advances in early detection and drug development in oncology, along with socioeconomic differences, racial inequities, lack of support, and barriers to accessing quality medical care, have created disparities in various marginalized populations. In this review, we will discuss the factors contributing to disparities in cardio-oncologic care in distinct populations, including Hispanic/Latinx, Black, Asian and Pacific Islander, indigenous populations, sex and gender minorities, and immigrants. Some factors that contribute to differences in outcomes in cardio-oncology include the prevalence of cancer screening rates, genetic cardiac/oncologic risk factors, cultural stressors, tobacco exposure rates, and physical inactivity. We will also discuss the barriers to cardio-oncologic care in these communities from the racial and socioeconomic context. Appropriate and timely cardiovascular and cancer care in minority groups is a critical component in addressing these disparities, and there need to be urgent efforts to address this widening gap.

Recruitment to a trial of antipsychotic reduction: impact of an acceptability study

OBJECTIVES

Pre-trial acceptability studies may boost recruitment, especially in trials comparing distinctly different interventions. We evaluated the impact of an acceptability study on recruitment to a randomised trial of antipsychotic reduction versus maintenance treatment and explored demographic and clinical predictors of subsequent enrolment.

METHODS

Participants with a diagnosis of a schizophrenia spectrum disorder who were taking antipsychotic medication were interviewed about their views of taking part in a future trial.

RESULTS

In a sample of 210 participants, 151 (71.9%) expressed an interest in taking part in the future trial, 16 (7.6%) said they might be interested, and 43 (20.5%) said they were not. Altruistic reasons were most commonly given for wanting to take part, and concern about randomisation for not wanting to. Ultimately 57 people enrolled in the trial (27.1% of the original sample). Eighty-five people who initially expressed an interest did not enrol due to declining or not being eligible (for clinical reasons). Women and people from a white ethnic background were more likely to enrol in the trial, but no illness or treatment-related characteristics were associated with enrolment.

CONCLUSION

An acceptability study can be a useful tool for recruitment to challenging trials, but it may over-estimate recruitment.

The frequency of major CYP2C19 genetic polymorphisms in women of Asian, Native Hawaiian and Pacific Islander subgroups

Aim: Prevalence of clinically actionable genetic variants of CYP2C19 is lacking in specific population subgroups. This study aims to assess the frequencies of CYP2C19*2, *3, and *17 in Asian, Native Hawaiian and Pacific Islander (NHPI) population subgroups compared with Europeans. Patients & methods: The study included repository DNA samples of 1064 women, 18 years or older, who self-reported as Filipino, Korean, Japanese, Native Hawaiian, Marshallese and Samoan. Results: The overall frequencies of CYP2C19*2 (25-36%) and CYP2C19*3 (2.5-10%) were significantly higher in all our subgroups than in Europeans (15 and 0.02%, respectively). The overall frequency of CYP2C19*17 was significantly lower in all our subgroups (1-6%) than in Europeans (21.7%). Conclusion: This is the first report on the frequencies of CYP2C19*2, *3, and *17 in women of Asian and NHPI descent with distinct population subgroup differences. Differential allele frequencies of CYP2C19 among population subgroups underscore the importance of increasing racial and ethnic diversity in pharmacogenetic research.

How do participants in clinical trials compare with other patients with schizophrenia?

We aimed to explore the clinical relevance of a multicentre, pragmatic randomised trial of antipsychotic reduction in people diagnosed with schizophrenia or psychosis The sample recruited for the antipsychotic reduction study (n = 69 people) was compared with the population of patients with an eligible diagnosis undergoing treatment in the same service (n = 3067 people), using routinely-collected, anonymised data. The trial sample was found to resemble the wider population in terms of the number of past admissions, the likelihood of having been subject to legal detention and the level of risk the patient was perceived to pose to themselves or others. There was a lower proportion of people from minority ethnic backgrounds in the trial sample. The results provide some reassurance that trial recruits were similar to the wider population in terms of the severity of their condition and did not comprise a highly select sample of people with milder problems. The different ethnic composition of the research sample is consistent with other research.

Effect of redundant clinical trials from mainland China evaluating statins in patients with coronary artery disease: cross sectional study

OBJECTIVE

To identify redundant clinical trials evaluating statin treatment in patients with coronary artery disease from mainland China, and to estimate the number of extra major adverse cardiac events (MACEs) experienced by participants not treated with statins in those trials.

DESIGN

Cross sectional study.

SETTING

2577 randomized clinical trials comparing statin treatment with placebo or no treatment in patients with coronary artery disease from mainland China, searched from bibliographic databases to December 2019.

PARTICIPANTS

250 810 patients with any type of coronary artery disease who were enrolled in the 2577 randomized clinical trials.

MAIN OUTCOME MEASURES

Redundant clinical trials were defined as randomized clinical trials that initiated or continued recruiting after 2008 (ie, one year after statin treatment was strongly recommended by clinical practice guidelines). The primary outcome is the number of extra MACEs that were attributable to the deprivation of statins among patients in the control groups of redundant clinical trials-that is, the number of extra MACEs that could have been prevented if patients were given statins. Cumulative meta-analyses were also conducted to establish the time points when statins were shown to have a statistically significant effect on coronary artery disease.

RESULTS

2045 redundant clinical trials were identified published between 2008 and 2019, comprising 101 486 patients in the control groups not treated with statins for 24 638 person years. 3470 (95% confidence interval 3230 to 3619) extra MACEs were reported, including 559 (95% confidence interval 506 to 612) deaths, 973 (95% confidence interval 897 to 1052) patients with new or recurrent myocardial infarction, 161 (132 to 190) patients with stroke, 83 (58 to 105) patients requiring revascularization, 398 (352 to 448) patients with heart failure, 1197 (1110 to 1282) patients with recurrent or deteriorated angina pectoris, and 99 (95% confidence interval 69 to 129) unspecified MACEs.

CONCLUSIONS

Of more than 2000 redundant clinical trials on statins in patients with coronary artery disease identified from mainland China, an extra 3000 MACEs, including nearly 600 deaths, were experienced by participants not treated with statins in these trials. The scale of redundancy necessitates urgent reform to protect patients.

Pharmacogenomics in Asian Subpopulations and Impacts on Commonly Prescribed Medications

Asians as a group comprise > 60% the world's population. There is an incredible amount of diversity in Asian and admixed populations that has not been addressed in a pharmacogenetic context. The known pharmacogenetic differences in Asian subgroups generally represent previously known variants that are present at much lower or higher frequencies in Asians compared with other populations. In this review we summarize the main drugs and known genes that appear to have differences in their pharmacogenetic properties in certain Asian populations. Evidence-based guidelines and summary statistics from the US Food and Drug Administration and the Clinical Pharmacogenetics Implementation Consortium were analyzed for ethnic differences in outcomes. Implicated drugs included commonly prescribed drugs such as warfarin, clopidogrel, carbamazepine, and allopurinol. The majority of these associations are due to Asians more commonly being poor metabolizers of cytochrome P450 (CYP) 2C19 and carriers of the human leukocyte antigen (HLA)-B*15:02 allele. The relative risk increase was shown to vary between genes and drugs, but could be > 100-fold higher in Asians. Specifically, there was a 172-fold increased risk of Stevens-Johnson syndrome and toxic epidermal necrolysis with carbamazepine use among HLA-B*15:02 carriers. The effects ranged from relatively benign reactions such as reduced drug efficacy to severe cutaneous skin reactions. These reactions are severe and prevalent enough to warrant pharmacogenetic testing and appropriate changes in dose and medication choice for at-risk populations. Further studies should be done on Asian cohorts to more fully understand pharmacogenetic variants in these populations and to clarify how such differences may influence drug response.

Asian Americans are less willing than other racial groups to participate in health research

Background

Asian Americans constitute 5% of the U.S. population. Their willingness to participate in research is important to examine because it influences participation rates and the representativeness of study results.

Methods

A total of 17,339 community members participated from six diverse Clinical and Translational Award (CTSA) sites. Community members were asked about their willingness to volunteer for eight different types of health research, their expectation of monetary compensation for research participation, their trust in research and researchers, their preferred language to receive health information, and their socio-demographic background. We examined Asian Americans' willingness to participate in various types of health research studies and compared their perceptions with other racial/ethnic groups (i.e., Asian n = 485; African-American n = 9516; Hispanic/Latino n = 1889; Caucasian n = 4760; and other minority n = 689).

Results

Compared to all other racial/ethnic groups, Asian Americans were less willing to participate in all eight types of health research. However, Asian Americans reported a lower amount of fair compensation for research participation than African-Americans and Hispanics/Latinos but were as likely to trust researchers as all other racial/ethnic groups.

Conclusion

Asian Americans are less willing to participate in health research than other racial/ethnic groups, and this difference is not due to dissatisfaction with research compensation or lower trust in researchers. Lack of trust in research and language barriers should be addressed to improve representativeness and generalizability of all populations in research.

Recruitment process of a Chinese immigrant study in Canada

The objectives of this article were to provide a comprehensive overview of the recruitment experience and participant characteristics in an antihypertensive dietary educational intervention pilot trial among Chinese Canadians. The recruitment was conducted in a community centre. Two recruitment approaches, self-referral and proactive recruitment, were used. Among 618 Chinese Canadians in the blood pressure screening, 105 (17.0%) individuals were eligible to participate in this trial. Of the 105 eligible individuals, 45 (42.9%) declined enrollment and 60 (57.1%) consented to participate in the trial and were recruited. The most common reason for refusal was being unable to access to the education location (n=19, 42.2%) followed by being too busy to participate (n=18, 40.0%). All participants were Chinese immigrants and the mean number of years living in Canada was 9.2. Most participants had low English proficiency, accepted Chinese culture more than Western culture, and had strong traditional health beliefs. It is concluded that both self-referral and proactive recruitment approaches were effective. Home-based interventions using Internet and telephone should be used as alternative delivery approaches to improve recruitment rate and facilitate participation.

Exploring Willingness of Elder Chinese in Houston to Participate in Clinical Research

Background and objectives

Inadequate minority participation in clinical research can threaten the applicability and strength of scientific findings. Previous research suggests that trial participation rates are lowest among Asian Americans, compared to other groups. This study explored barriers to clinical research participation among elder Chinese living in Houston, Texas. Additionally we administered the Trust in Medical Researchers Scale (TIMRS), used previously in researching trust in medical researchers as related to research participation.

Design

In this mixed methods study, a semi-structured interview, including the TIMRS were administered to 30 adults of Chinese ancestry aged 50 years or older recruited from a Chinese community center. Interviews were conducted in English, Mandarin and Cantonese and independently coded and analyzed using thematic content analysis. TIMRS scores were calculated for participants.

Results

Participants were 70% female, 70% were 60 or elder, all were foreign born and on average lived in the US for 21.8 years. Participants perceived risks to research participation and preferred language concordant research staff. Interviewees were more willing to participate if they perceived personal and community health-related benefits. The overall TIMRS score was 23.9 (±5.0), lower than the overall TIMRS for Whites in a previous study (P < 0.001).

Conclusions

The barriers and facilitators to research participation confirmed previous research among Asians. Our participant TIMRS scores were consistent with decreased levels of trust observed in the original TIMRS study for African Americans as compared and lower than Whites. Employing strategies that utilize language concordant staff who build trust with participants may aid in recruiting elder Chinese, especially if the research is personally relevant to those being recruited.

Overcoming barriers to recruiting ethnic minorities to mental health research: a typology of recruitment strategies

BACKGROUND

The ethnic minority population in developed countries is increasing over time. These groups are at higher risk of mental illness and demonstrate lower participation in research. Published evidence suggests that multiple factors like stigma, lack of trust, differences in explanatory models, logistical issues and lack of culturally aware researchers act as barriers to ethnic minority recruitment into mental health research. To reduce inequalities in participation, there is a need to devise innovative and culturally sensitive recruitment strategies. It is important that researchers share their experience of employing these strategies so that ethnic minority participation can be facilitated.

METHODS

We previously published a systematic review of barriers to recruiting ethnic minority participants into mental health research. The nine papers included in our prior review formed the basis for developing a typology of barriers to recruiting ethnic minorities into mental health research. This typology identified 33 barriers, described under five themes. We further extracted data on the strategies used to overcome these recruitment barriers, as described in the included studies.

RESULTS

The strategies employed by the authors could be matched to all but two barriers (psychopathology/substance misuse and limited resource availability). There was evidence that multiple strategies were employed, and that these depended upon the population, clinical set-up and resources available.

CONCLUSIONS

This typology of strategies to overcome barriers to recruiting ethnic minorities provides guidance on achieving higher rates of recruitment. It is important that researchers plan to deploy these strategies well in advance of initiating recruitment. Whilst adopting these strategies, the authors have not been able to quantify the positive impact of these strategies on recruitment. The typology should encourage researchers to employ these strategies in future research, refine them further and quantitatively evaluate their impact.

Increasing Asian American participation in clinical trials by addressing community concerns

Background Asian Americans are underrepresented in clinical trials, but little is known about the factors that contribute to clinical trial participation in this population. Purpose The purpose of this study was to identify knowledge, barriers, facilitators, and cultural influences on participating in clinical trials among three Asian American ethnic groups. Concurrently, we sought to identify mechanisms and messages to facilitate dissemination of information and to identify strategies to promote clinical trial participation in this population. Methods Eight focus groups were conducted (n = 103) with Chinese (four groups), Korean (two groups), and Vietnamese (two groups) Americans. Each group was conducted with a moderator and a translator using a standardized guide. Results Participants discuss the benefits of contributing to science, future generations, and their families by being in clinical trials. Some participants think clinical trials would give hope to those with terminal illnesses. A doctor's recommendation, being sick, and needing more options for treatment are motivators for Asian Americans. Having some guarantee of treatment effectiveness and lack of side effects facilitates participation. Cultural or religious beliefs are not believed to prevent clinical trial participation. Limitations This qualitative, two-site study included three Asian American ethnic groups and is not meant to establish prevalence of beliefs. Conclusion Asian Americans need more information about clinical trials and their benefits to science and the larger community. Health-care providers can play pivotal roles in enhancing recruitment of Asian Americans. Basing recruitment goals on percentage representation in most US geographic areas does not provide sufficient numbers to allow for analysis of minorities like Asian American groups. The discovery of important group-specific harms and benefits depends on greater participation of racial/ethnic subgroups.

A review on the genetic, environmental, and lifestyle aspects of the early-life origins of cardiovascular disease

This article is a comprehensive review on developmental origins of health and disease regarding various factors related to the origins of cardiovascular diseases from early life. It presents a summary of the impacts of various factors such as epigenetics; gene-environment interaction; ethnic predisposition to cardiovascular diseases and their underlying risk factors; prenatal factors; fetal programming; maternal weight status and weight gain during pregnancy; type of feeding during infancy; growth pattern during childhood; obesity; stunting; socioeconomic status; dietary and physical activity habits; active, secondhand, and thirdhand smoking, as well as environmental factors including air pollution and global climate change on the development and progress of cardiovascular diseases and their risk factors. The importance of early identification of predisposing factors for cardiovascular diseases for primordial and primary prevention of cardiovascular diseases from early life is highlighted.

The impact of a community-based clinical trial educational intervention among underrepresented Chinese Americans

BACKGROUND

Clinical trials are a critical resource for the discovery of new prevention, diagnostic, and treatment methods for cancer. The most effective prevention and treatment modalities are based on previous clinical trial results. However, participation in clinical trials is underrepresented by racial/ethnic minority populations, Asian Americans in particular. Asian Americans are the least represented of any ethnic groups in clinical trials. The purpose of this study is to develop and evaluate a culturally and linguistically appropriate community-based educational intervention to increase knowledge of and intent to participate in cancer clinical trials among underrepresented Chinese Americans.

METHODS

Community-Based Participatory Research approach was used to guide the development, cultural tailoring, implementation, and evaluation of clinical trial intervention. First, 22 Asian community representatives were recruited as community health educators (CHE) who received 12-hour training on clinical trial education. Second, 262 members were recruited from 11 Chinese community organizations. Of those recruited, a total of 247 eligible Chinese enrolled and participated in the clinical trial education delivered by trained CHEs. Participants completed pretest before and posttest after the intervention.

RESULTS

Fifteen of 21 measures of clinical trial knowledge showed significant changes post the intervention (P < 0.05). Education remained the sole demographic factor increasing clinical trial knowledge in multivariate analysis.

CONCLUSION

Clinical trial education should emphasize both benefits to science and the larger Asian community. This community-based clinical trial intervention demonstrated promising results and has potential to enhance recruitment and participation in clinical trial research among the underrepresented Asian Americans.

IMPACT

Improving clinical trial participation in the fast-growing Asian American population is key to dissemination of health innovations targeted to diminish health disparities.

Recruiting South Asians to a lifestyle intervention trial: experiences and lessons from PODOSA (Prevention of Diabetes & Obesity in South Asians)

Background

Despite the growing emphasis on the inclusion of ethnic minority patients in research, there is little published on the recruitment of these populations especially to randomised, community based, lifestyle intervention trials in the UK.

Methods

We share our experience of recruitment to screening in the PODOSA (Prevention of Diabetes and Obesity in South Asians) trial, which screened 1319 recruits (target 1800) for trial eligibility. A multi-pronged recruitment approach was used. Enrolment via the National Health Service included direct referrals from health care professionals and written invitations via general practices. Recruitment within the community was carried out by both the research team and through our partnerships with local South Asian groups and organisations. Participants were encouraged to refer friends and family throughout the recruitment period.

Results

Health care professionals referred only 55 potential participants. The response to written invitations via general practitioners was 5.2%, lower than reported in other general populations. Community orientated, personal approaches for recruitment were comparatively effective yielding 1728 referrals (82%) to the screening stage.

Conclusions

The PODOSA experience shows that a community orientated, personal approach for recruiting South Asian ethnic minority populations can be successful in a trial setting. We recommend that consideration is given to cover recruitment costs associated with community engagement and other personalised approaches. Researchers should consider prioritising approaches that minimise interference with professionals' work and, particularly in the current economic climate, keep costs to a minimum. The lessons learned in PODOSA should contribute to future community based trials in South Asians.

Trial Registration

Current Controlled Trials ISRCTN25729565