Challenge and Yield of Enrolling Racially and Ethnically Diverse Patient Populations in Low Event Rate Clinical Trials

Updating and evaluating a research best practices training course for social and behavioral research professionals

Introduction

The clinical and translational research workforce involved in social and behavioral research (SBR) needs to keep pace with clinical research guidance and regulations. Updated information and a new module on community and stakeholder engagement were added to an existing SBR training course. This article presents evaluation findings of the updated course for the Social and Behavioral Workforce.

Methods and Materials

Participants working across one university were recruited. Course completers were sent an online survey to evaluate the training. Some participants were invited to join in a focus group to discuss the application of the training to their work. We performed descriptive statistics and conducted a qualitative analysis on focus group data.

Results

There were 99 participants from diverse backgrounds who completed the survey. Most reported the training was relevant to their work or that of the study teams they worked with. Almost half (46%) indicated they would work differently after participating. Respondents with community or stakeholder engaged research experience vs. those without were more likely to report that the new module was relevant to study teams they worked with (t = 5.61, p = 0.001), and that they would work differently following the training (t = 2.63, p = 0.01). Open-ended survey responses (n = 99) and focus group (n = 12) data showed how participants felt their work would be affected by the training.

Conclusion

The updated course was rated highly, particularly by those whose work was related to the new course content. This course provides an up-to-date resource for the training and development for the Social and Behavioral Workforce.

Evaluation of an online research best practices training for community health workers and promotoras

Introduction

Community health workers and promotoras (CHW/Ps) have a fundamental role in facilitating research with communities. However, no national standard training exists as part of the CHW/P job role. We developed and evaluated a culturally- and linguistically tailored online research best practices course for CHW/Ps to meet this gap.

Methods

After the research best practices course was developed, we advertised the opportunity to CHW/Ps nationwide to complete the training online in English or Spanish. Following course completion, CHW/Ps received an online survey to rate their skills in community-engaged research and their perceptions of the course using Likert scales of agreement. A qualitative content analysis was conducted on open-ended response data.

Results

104 CHW/Ps completed the English or Spanish course (n = 52 for each language; mean age 42 years SD ± 12); 88% of individuals identified as female and 56% identified as Hispanic, Latino, or Spaniard. 96%-100% of respondents reported improvement in various skills. Nearly all CHW/Ps (97%) agreed the course was relevant to their work, and 96% felt the training was useful. Qualitative themes related to working more effectively as a result of training included enhanced skills, increased resources, and building bridges between communities and researchers.

Discussion

The CHW/P research best practices course was rated as useful and relevant by CHW/Ps, particularly for communicating about research with community members. This course can be a professional development resource for CHW/Ps and could serve as the foundation for a national standardized training on their role related to research best practices.

Twenty-year trends in racial and ethnic enrollment in large diabetes randomized controlled trials

BACKGROUND

Lack of representativeness in Black, Indigenous, and People of Colour (BIPOC) enrollment could compromise the generalizability of study results and health equity. This study aimed to examine trends in BIPOC groups enrollment in diabetes randomized controlled trials (RCTs) and to explore the association between trial factors and high-enrollment of BIPOC groups.

METHODS

We systematically searched the literature on large diabetes RCTs with a sample size of ≥ 400 participants published between 2000 and 2020. We assessed temporal trends in enrollment of racial and ethnic groups in the included trials. Logistic and linear regression analyses were used to explore the relationship between trial factors and the high-enrollment defined by median enrollment rate.

RESULTS

A total of 405 RCTs were included for analyses. The median enrollment rate of BIPOC groups was 24.0%, with 6.4% for the Black group, 11.2% for Hispanic, 8.5% for Asian, and 3.0% for other BIPOC groups respectively. Over the past 20 years, the BIPOC enrollment showed an increased trend in the diabetes RCTs, ranging from 20.1 to 28.4% (P for trend = 0.041). A significant trend towards increased enrollment for Asian group was observed. We found that weekly or daily intervention frequency (OR = 0.48, 95% CI: 0.26, 0.91) and duration of intervention > 6.5 month (OR = 0.59, 95% CI: 0.37, 0.95) were significantly related to decreased odds of high-enrollment, while type 2 diabetes (OR = 1.44, 95% CI: 1.04, 1.99) was associated with high-enrollment of BIPOC groups.

CONCLUSIONS

The enrollment of BIPOC was found to increase in large diabetes RCTs over the past two decades; some trial factors may be significantly associated with BIPOC enrollment. These findings may highlight the importance of enrollment of BIPOC groups and provide insights into the design and implementation of future clinical trials in diabetes.

Social determinants of participant recruitment and retention in a prospective cohort study of pediatric mild traumatic brain injury

Background

Prior studies have shown poor recruitment and retention of minoritized groups in clinical trials.

Objective

To examine several social determinants as predictors of consent to participate and retention as part of a prospective, longitudinal cohort study of children 8–16 with either mild traumatic brain injury (mild TBI) or orthopedic injury (OI).

Methods

Children and families were recruited during acute visits to emergency departments (ED) in two large children's hospitals in the midwestern United States for a prospective, longitudinal cohort study of children 8–16 with either mild TBI or OI.

Results

A total of 588 (mild TBI = 307; OI = 281) eligible children were approached in the ED and 315 (mild TBI = 195; OI = 120) were consented. Children who consented did not differ significantly from those who did not consent in sex or age. Consent rates were higher among Black (60.9%) and multi-racial (76.3%) children than white (45.3%) children. Among the 315 children who consented, 217 returned for a post-acute assessment (mild TBI = 143; OI = 74), a retention rate of 68.9%. Participants who were multi-racial (96.6%) or white (79.8%) were more likely to return for the post-acute visit than those who were Black (54.3%).

Conclusions

Racial differences exist in both recruitment and retention of participants in a prospective, longitudinal cohort of children with mild TBI or OI. Further work is needed to understand these differences to ensure equitable participation of minoritized groups in brain injury research.

Health Screening Program to Enhance Enrollment of Women and Minorities in CREST-2

BACKGROUND AND PURPOSE

The CREST-2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial) consists of 2 parallel randomized stroke prevention trials in patients with asymptomatic high-grade stenosis of the cervical carotid artery. The purpose of this report is to detail the outcomes of a health screening effort to increase trial enrollment of women and minorities.

METHODS

Life Line screening (LLS) conducts nationwide screening for vascular disease. Screenings within a 50-mile radius of each CREST-2 center were identified for participation in a joint CREST-LLS program over the course of one year (November 2018 to October 2019) whereby patients with an abnormal carotid ultrasound were referred to the local CREST-2 center for further workup, management, and potential consideration for trial enrollment.

RESULTS

LLS completed the screening of 588 198 individuals in 29 732 zip codes across the United States. Of those, 230 021 individuals were screened at events occurring near a CREST-2 clinical center and 646 (0.3%) were found to have abnormal carotid ultrasound findings. Each of the 646 individuals was contacted by CREST-LLS program staff for permission to be referred to their local CREST-2 center; 200 (31%) consented to be contacted by CREST-2. Of those, 39 (19.5%) agreed to be, and were, evaluated at their local CREST-2 center. High-grade stenosis was confirmed in 27 patients. A total of 3 patients were eligible for the trial and were enrolled, one woman but no racial/ethnic minorities.

CONCLUSIONS

The LLS program appears to identify community-living individuals with high-grade carotid stenosis through ultrasonography. However, the prevalence of abnormal carotid findings was low. In addition, screening and offering participation into the CREST-2 trial had no substantial impact on the proportion of women and minorities enrolled in the trial. Additional innovative strategies are needed to promote enrollment of diverse patients with carotid stenosis into stroke prevention trials.

Race Differences in High-Grade Carotid Artery Stenosis

Background and Purpose

Despite a higher incidence of stroke and a more adverse cardiovascular risk factor profile in Blacks and Hispanics compared with Whites, carotid artery revascularization is performed less frequently among these subpopulations. We assessed racial differences in high-grade (≥70% diameter-reducing) carotid stenosis.

Methods

Consecutive clients in a Nationwide Life Line for-Profit Service to screen for vascular disease, 2005 to 2019 were evaluated in a cross-sectional study. The prevalence of high-grade stenosis, defined by a carotid ultrasound peak systolic velocity of ≥230 cm/s, was assessed. Participants self-identified as White, Black, Hispanic, Asian, Native American, or other. Race/ethnic differences were assessed using Poisson regression. The number of individuals in the United States with high-grade stenosis was estimated by applying prevalence estimates to 2015 US Census population estimates.

Results

The prevalence of high-grade carotid stenosis was estimated in 6 130 481 individuals. The prevalence of high-grade stenosis was higher with increasing age in all race-sex strata. Generally, Blacks and Hispanics had a lower prevalence of high-grade stenosis compared with Whites, while Native Americans had a higher prevalence. For example, for men aged 55 to 65, the relative risk of stenosis compared with Whites was 0.40 (95% CI, 0.29–0.55) and 0.61 (95% CI, 0.46–0.81) for Blacks and Hispanics, respectively; and 1.53 (95% CI, 1.12–2.10) for Native Americans. When these prevalence estimates were applied to the Census estimates of the US population, an estimated 327 721 individuals have high-grade stenosis, of whom 7% are Black, 7% Hispanic, and 43% women.

Conclusions

Despite their having a more adverse cardiovascular risk profile, there was a lower prevalence of high-grade carotid artery stenosis for both the Black and Hispanic relative to the White clients. This lower prevalence of high-grade stenosis is a potential contributor to the lower use of carotid revascularization procedures in these minority populations.

Does study subject diversity influence cardiology research site performance?: Insights from 2 U.S. National Coronary Stent Registries

BACKGROUND

Minorities and women are underrepresented in cardiovascular research. Whether their higher enrollment can be predicted or influences research site performance is unclear.

METHODS

We evaluated 104 sites that enrolled 4,184 patients in the U.S. Platinum Diversity (PD) and Promus Element Plus (PE Plus) studies (2012 to 2016). Research sites were ranked from lowest to highest minority and female enrollment, respectively. United States Census Bureau division and core-based statistical area (CBSA) populations were determined for each site and the following study performance metrics compared across quartiles of minority and female enrollment, respectively: (1) study subject enrollment rate (SER), (2) time to first patient enrolled, (3) rate of follow-up visits not done, (4) rate of follow-up visits out of window, and (5) protocol deviation rate (PDR). Multivariable regression was used to predict SER and PDR.

RESULTS

Minority enrollment varied by region (P = .025) and population (P = .024) with highest recruitment noted in the Pacific, West South Central, South Atlantic, Mid-Atlantic and East North Central divisions. Female enrollment bore no relationship to region (P = .67) or population (P = .40). Median SER was similar in sites withi the highest vs lowest quartile of minority enrollment (SER of 4 vs 5 patients per month, respectively, P =0.78) and highest vs. lowest female enrollment (SER of 4 vs 4, respectively, P = .21). Median PDR was lower in sites within the highest vs lowest minority enrollment (0.23 vs 0.50 PDs per patient per month, respectively, P = .01) and highest vs. lowest female enrollment (0.28 vs. 0.37 PDs per patient per month, respectively, P = .04). However, this relationship did not persist after multivariable adjustment. All other site performance metrics were comparable across quartiles of minority and female enrollment.

CONCLUSIONS

Minority, but not female enrollment, correlated with research site geographic region and surrounding population. High enrollment of minorities and women did not influence study performance metrics. These findings help inform future strategies aimed at increasing clinical trial diversity.

TRIAL REGISTRATION

The PD and PE Plus studies are registered at www.clinicaltrials.gov under identifiers NCT02240810 and NCT01589978, respectively.

KEY POINTS

Question: Does the enrollment of more Blacks, Hispanics and women in US cardiovascular research studies influence the overall rate of study subject enrollment and/or other key study site performance metrics and can diverse enrollment be predicted?

FINDINGS

In this pooled analysis of 104 sites that enrolled 4,184 patients in the Platinum Diversity and Promus Element Plus Post-Approval Studies, we found that the enrollment of higher proportions of underrepresented minorities and women was univariately associated with lower protocol deviation rates while having no effect on other site performance metrics. A site's geographic location and surrounding population predicted minority, but not female enrollment. Meaning: These findings suggest that cardiovascular research subject diversity may be predicted from site characteristics and enhanced without compromising key study performance metrics. These insights help inform future strategies aimed at improving clinical trial diversity.

Time- and Race-Specific Haematological Reference Intervals for Healthy Volunteer Trials: A Retrospective Analysis of Pooled Data From Multiple Phase I Trials

Most UK hospitals, laboratories, and research institutions use uniform reference intervals (RI) that do not take into account known diurnal and racial variation in total white blood cells (WBC) count and its constituent parameters. These risks of excluding potentially suitable ethnic minority volunteers from participating in phase I clinical trials could call into question the validity of a trial’s findings or limit its scientific applications and ability to accurately observe drug effects upon WBC parameters. This study pools data from multiple phase I trials, assesses the effects of race and time of day on WBC count, and compares it to the existing literature to establish race and time-specific RIs. A total 13,332 venous blood samples obtained from 7,157 healthy male and female volunteers at the time of screening or admission (predosing) who took part in 35 phase I trials over a period of seven years were pooled and the data were analyzed using generalised estimating equation models. Adjusted RI of total WBC count and its individual parameters were then calculated according to time of day (morning vs. evening) for both black and nonblack populations. This study indicates that black individuals on average had lower total WBC, neutrophil, monocyte, eosinophil, and basophil counts than individuals from nonblack racial groups. Black volunteers had higher mean lymphocyte counts relative to their nonblack counterparts. These differences were deemed statistically significant. Statistically significant increases in total WBC, neutrophil, lymphocyte, and monocyte counts were also observed over the course of daily sampling. Eosinophil counts decreased during this time period, but this finding was only statistically significant in the nonblack population. Despite an observed mild diurnal increase in basophil count in both populations, this was not considered statistically significant. This high-powered study adds significant weight to the known evidence for diurnal and racial variation in WBC parameters. Importantly, it proposes specific RIs that more precisely reflect race and time of day. These could ensure increased participation of black volunteers in clinical trials for improved population representation. Furthermore, the proposed RIs allow for more accurate postdose safety monitoring and reporting, and ensure improved monitoring of postdose WBC count changes.

Editor's Choice - Overview of Primary and Secondary Analyses From 20 Randomised Controlled Trials Comparing Carotid Artery Stenting With Carotid Endarterectomy

OBJECTIVES

The aim of this review was to carry out primary and secondary analyses of 20 randomised controlled trials (RCTs) comparing carotid endarterectomy (CEA) with carotid artery stenting (CAS).

METHODS

A systematic review and meta-analysis of data from 20 RCTs (126 publications) was carried out.

RESULTS

Compared with CEA, the 30 day death/stroke rate was significantly higher after CAS in seven RCTs involving 3467 asymptomatic patients (odds ratio [OR] 1.64, 95% confidence interval [CI] 1.02-2.64) and in 10 RCTs involving 5797 symptomatic patients (OR 1.71, 95% CI 1.38-2.11). Excluding procedural risks, late ipsilateral stroke was about 4% at 9 years for both CEA and CAS, i.e., CAS was durable. Reducing procedural death/stroke after CAS may be achieved through better case selection, e.g., performing CEA in (i) symptomatic patients aged > 70 years; (ii) interventions within 14 days of symptom onset; and (iii) situations where stroke risk after CAS is predicted to be higher (segmental/remote plaques, plaque length > 13 mm, heavy burden of white matter lesions [WMLs], where two or more stents might be needed). New WMLs were significantly more common after CAS (52% vs. 17%) and were associated with higher rates of late stroke/transient ischaemic attack (23% vs. 9%), but there was no evidence that new WMLs predisposed towards late cognitive impairment. Restenoses were more common after CAS (10%) but did not increase late ipsilateral stroke. Restenoses (70%-99%) after CEA were associated with a small but significant increase in late ipsilateral stroke (OR 3.87, 95% CI 1.96-7.67; p < .001).

CONCLUSIONS

CAS confers higher rates of 30 day death/stroke than CEA. After 30 days, ipsilateral stroke is virtually identical for CEA and CAS. Key issues to be resolved include the following: (i) Will newer stent technologies and improved cerebral protection allow CAS to be performed < 14 days after symptom onset with risks similar to CEA? (ii) What is the optimal volume of CAS procedures to maintain competency? (iii) How to deliver better risk factor control and best medical treatment? (iv) Is there a role for CEA/CAS in preventing/reversing cognitive impairment?