Demographic recruitment bias of adults in United States randomized clinical trials by disease categories between 2008 to 2019: a systematic review and meta-analysis

Intra-neighborhood associations between residential greenness and blood pressure

INTRODUCTION

Previous investigations have reported that individuals living in greener neighborhoods have better cardiovascular health. It is unclear whether the effects reported at large geographic scales persist when examined at an intra-neighborhood level. The effects of greenness have not been thoroughly examined using high-resolution metrics of greenness exposure, and how they vary with spatial scales of assessment or participant characteristics.

METHODS

We conducted a cross-sectional assessment of associations between blood pressure and multiple high-resolution measures of residential area greenness in spatially concentrated HEAL Study cohort of the Green Heart Project. We employed generalized linear models, accounting for individual-level covariates, to examine associations between different high-resolution measures of greenness and blood pressure among 667 participants in a 4 sq. mile contiguous neighborhood area in Louisville, KY.

RESULTS

In adjusted models, we observed significant inverse associations between residential greenness, measured by leaf area index (LAI), and systolic blood pressure (SBP) within 150-250 m and 500 m of homes, but not for Normalized Difference Vegetation Index (NDVI) or grass cover. Weaker associations were also found with diastolic blood pressure (DBP). Significant positive associations were observed between LAI and SBP among participants who reported being female, White, without obesity, non-exercisers, non-smokers, younger age, of lower income, and who had high nearby roadway traffic. We found few significant associations between grass cover and SBP, but an inverse association in those with obesity, but positive associations for those without obesity.

CONCLUSIONS

We found that leaf surface area of trees around participants home is strongly associated with lower blood pressure, with little association with grass cover. These effects varied with participant characteristics and spatial scales. More research is needed to test causative links between greenspace types and cardiovascular health and to develop population-, typology-, and place-based evidence to inform greening interventions.

Effectiveness and predictors of weight loss response to phentermine plus lifestyle modifications among youth in a paediatric weight management clinical setting

BACKGROUND

Anti-obesity medications (AOMs) are promising lifestyle modification (LSM) adjuncts for obesity treatment, and phentermine is commonly prescribed in paediatric weight management clinics. Determining 'real-world' AOM effectiveness and characteristics predicting response is important.

OBJECTIVES

We sought to describe phentermine plus LSM effectiveness and identify baseline characteristics predicting response.

METHODS

This was a retrospective cohort study among youth seen in a US academic-based weight management clinic from 2012 to 2020. Baseline characteristics (e.g., body mass index (BMI), liver transaminases, eating-related behaviours) and outcomes (%BMI of 95th percentile (%BMIp95), BMI, %BMI change, weight) were determined through electronic health records and intake surveys.

RESULTS

Among 91 youth prescribed phentermine plus LSM over 8 years (mean %BMIp95 150%), %BMIp95 was statistically significantly reduced at 1.5, 3, 6 and 12 months (peak reduction 10.9 percentage points at 6 months; p < 0.001). Considering multiple comparisons, the presence of baseline elevated alanine aminotransferase was associated with statistically significant smaller 1.5-month %BMIp95 reductions (p = 0.001) and higher food responsiveness with smaller 3- (p = 0.001) and 6-month (p < 0.001) reductions.

CONCLUSIONS

Phentermine plus LSM reduced %BMIp95 among youth in a weight management clinic, and baseline characteristics may help determine those more or less likely to respond. Prospective studies are needed to further characterize effectiveness and confirm response predictors.

Temporal trends and characteristics associated with racial, ethnic, and sex representation in COVID-19 clinical trials: A systematic review and meta-analysis

BACKGROUND

Early in the pandemic, extensive attention was cast on limited inclusion of historically underrepresented patient populations in COVID-19 clinical trials. How diverse representation improved following these initial reports remains unclear.

METHODS

PubMed, Embase and the Cochrane Library were searched (through April 2024) for US-based COVID-19 trials. Utilizing random-effects, we compared expected proportions of trial participants from racial and ethnic groups and of female sex between trials enrolling primarily in 2020 versus primarily 2021-2022. Meta-regression was performed to assess associations between trial characteristics and group representation.

RESULTS

We retrieved 157 studies comprising 198,012 participants. White (2020: 63.1% [95% CI, 60.8%-67.3%]; 2021-2022: 73.8% [95% CI, 71.5%-76.0%]) and female representation (2020: 46.1% [95% CI, 44.7%-47.4%)]; 2021-2022: 51.1% [95% CI, 49.3%-52.8%) increased across enrollment periods. Industry-sponsored trials were associated with higher White (coefficient, 0.10 [95% CI, 0.03-0.18]) and Hispanic or Latinx representation (coefficient, 0.16 [95% CI, 0.08-0.25]) and lower Asian (coefficient, -0.03 [95% CI, -0.06- -0.003]) and female representation (coefficient, -0.03 [95% CI, -0.07- -0.002]). Outpatient trials were associated with higher White (coefficient, 0.20 [95% CI, 0.13-0.26]) and female representation (coefficient, 0.16 [95% CI, 0.13-0.18]), and lower Black representation (coefficient, -0.10 [95% CI, -0.10- -0.08]).

CONCLUSIONS

Despite improved female representation in COVID-19 trials over time, there was no clear increase in non-White representation. Trial characteristics such as primary sponsor, clinical setting, and intervention type correlate with representation of specific demographic groups and should be considered in future efforts to improve participant diversity.

Clinical effectiveness and predictors of response to topiramate plus lifestyle modification in youth with obesity seen in a weight management clinical setting

Introduction

Obesity affects approximately 20% of U.S. youth. Anti-obesity medications (AOMs) are promising lifestyle modification adjuncts for obesity treatment, and topiramate is commonly prescribed in pediatric weight management clinics. It is important to determine "real-world" effectiveness of AOMs and, given shifts towards personalized approaches, characteristics potentially predicting better or worse response. We therefore sought to describe clinical effectiveness from topiramate plus lifestyle modification, and to determine if baseline phenotypic characteristics are associated with better or worse response.

Methods

We performed a retrospective cohort study (2012-2020) among youth (<18 years old) followed in a U.S. academic-based weight management clinic. Baseline characteristics (i.e., body mass index (BMI), liver function tests, eating-related behaviors) and outcomes (%BMI of 95th percentile (%BMIp95), BMI, percent %BMI change, weight) were determined through review of electronic health records and clinic intake survey data.

Results

Among 282 youth prescribed topiramate plus lifestyle modifications (mean baseline age 12.7 years, %BMIp95 144%), %BMIp95 and percent BMI change were statistically significantly reduced at each time point (1.5-, 3-, 6-, and 12-month %BMIp95 reductions: -2.2, -3.9, -6.6, and -9.3 percentage points, respectively; percent BMI reduction: -1.2%, -1.9%, -3.2%, and -3.4%, respectively; all p<0.01). Considering multiple comparisons, no baseline characteristics statistically significantly predicted response at any time point.

Conclusions

We found that topiramate plus lifestyle modification reduced %BMIp95 and BMI among youth in a weight management clinical setting, and that no baseline characteristics evaluated were associated with response. These results should be considered preliminary given the observational nature of this study, and prospective studies are needed to further characterize clinical effectiveness and identify and confirm potential predictors of response.

A systematic review of ethnic minority participation in randomised controlled trials of systemic therapies for gynecological cancers

OBJECTIVE

Randomised controlled trials (RCTs) must include ethnic minority patients to produce generalisable findings and ensure health equity as cancer incidence rises globally. This systematic review examines participation of ethnic minorities in RCTs of licensed systemic anti-cancer therapies (SACT) for gynecological cancers, defining the research population and distribution of research sites to identify disparities in participation on the global scale.

METHODS

A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Phase II and III RCTs of licensed therapies for gynecological cancers published 01/11/2012-01/11/2022 that reported patient race/ethnicity were included. Extracted data included race/ethnicity and research site location. RCT populations were aggregated and participation of groups compared. Global distribution of research sites was described.

RESULTS

26 RCTs met inclusion criteria of 351 publications included in full-text screening, representing 17,041 patients. 79.8% were "Caucasian", 9.1% "East Asian", 3.7% "Black/African American" and 6.1% "Other, Unknown, Not Reported". "Caucasian" patients participated at higher rates than all other groups. Of 5,478 research sites, 80.1% were located in North America, 13.0% in Europe, 3.4% in East Asia, 1.3% in the Middle East, 1.3% in South America and 0.8% in Australasia.

CONCLUSIONS

Ethnic minorities formed smaller proportions of RCT cohorts compared to the general population. The majority of sites were located in North America and Europe, with few in other regions, limiting enrollment of South Asian, South-East Asian and African patients in particular. Efforts to recruit more ethnic minority patients should be made in North America and Europe. More sites in underserved regions would promote equitable access to RCTs and ensure findings are generalisable to diverse groups. This review assessed the global population enrolled in contemporary RCTs for novel therapies now routinely given for gynecological cancers, adding novel understanding of the global distribution of research sites.

Challenges, unmet needs and future directions - a critical evaluation of the clinical trial landscape in schizophrenia research

INTRODUCTION

Developing novel antipsychotic mechanisms of action and repurposing established compounds for the treatment of schizophrenia is of utmost importance to improve relevant symptom domains and to improve the risk/benefit ratio of antipsychotic compounds. Novel trial design concepts, pathophysiology-based targeted treatment approaches, or even the return to old values may improve schizophrenia outcomes in the future.

AREAS COVERED

In this review of the clinical trial landscape in schizophrenia, we present an overview of the challenges and gaps in current clinical trials and elaborate on potential solutions to improve the outcomes of people with schizophrenia.

EXPERT OPINION

The classic parallel group design may limit substantial advantages in drug approval or repurposing. Collaborative approaches between regulatory authorities, industry, academia, and funding agencies are needed to overcome barriers in clinical schizophrenia research to allow for meaningful outcome improvements for the patients.

Examining Diversity in Digital Therapeutics Clinical Trials: Descriptive Analysis

BACKGROUND

Digital therapeutics (DTx) are an emerging class of software-based medical therapies helping to improve care access and delivery. As we leverage these digital health therapies broadly in clinical care, it is important to consider sociodemographic representation underlying clinical trials data to ensure broad application to all groups.

OBJECTIVE

We review current sociodemographic representation in DTx clinical trials using data from the Digital Therapeutics Alliance Product Library database.

METHODS

We conducted a descriptive analysis of DTx products. We analyzed 15 manuscripts associated with 13 DTx products. Sociodemographic information was retrieved and compared with the US population's demographic distribution.

RESULTS

The median study size and age of participants were 252 and 43.3 years, respectively. Of the 15 studies applicable to this study, 10 (67%) reported that females made up 65% or greater of the study cohort. A total of 14 studies reported race data with Black or African American and Asian American individuals underrepresented in 9 and 11 studies, respectively. In 7 studies that reported ethnicity, Hispanics were underrepresented in all 7 studies. Furthermore, 8 studies reported education levels, with 5 studies reporting populations in which 70% or greater had at least some college education. Only 3 studies reported health insurance information, each reporting a study cohort in which 100% of members were privately insured.

CONCLUSIONS

Our findings indicate opportunities for improved sociodemographic representation in DTx clinical trials, especially for underserved populations typically underrepresented in clinical trials. This review is a step in examining sociodemographic representation in DTx clinical trials to help inform the path forward for DTx development and testing.

Demographic and Socioeconomic Factors in Prospective Retina-Focused Clinical Trial Screening and Enrollment

Historically marginalized populations are disproportionately affected by many diseases that commonly affect the retina, yet they have been traditionally underrepresented in prospective clinical trials. This study explores whether this disparity affects the clinical trial enrollment process in the retina field and aims to inform future trial recruitment and enrollment. Age, gender, race, ethnicity, preferred language, insurance status, social security number (SSN) status, and median household income (estimated using street address and zip code) for patients referred to at least one prospective, retina-focused clinical trial at a large, urban, retina-based practice were retrospectively extracted using electronic medical records. Data were collected for the 12-month period from 1 January 2022, through 31 December 2022. Recruitment status was categorized as Enrolled, Declined, Communication (defined as patients who were not contacted, were contacted with no response, were waiting for a follow-up, or were scheduled for screening following a clinical trial referral.), and Did Not Qualify (DNQ). Univariable and multivariable analyses were used to determine significant relationships between the Enrolled and Declined groups. Among the 1477 patients, the mean age was 68.5 years old, 647 (43.9%) were male, 900 (61.7%) were White, 139 (9.5%) were Black, and 275 (18.7%) were Hispanic. The distribution of recruitment status was: 635 (43.0%) Enrolled, 232 (15.7%) Declined, 290 (19.6%) Communication, and 320 (21.7%) DNQ. In comparing socioeconomic factors between the Enrolled and Declined groups, significant odds ratios were observed for age (p < 0.02, odds ratio (OR) = 0.98, 95% confidence interval (CI) [0.97, 1.00]), and between patients who preferred English versus Spanish (p = 0.004, OR = 0.35, 95% CI [0.17, 0.72]. Significant differences between the Enrolled and Declined groups were also observed for age (p < 0.05), ethnicity (p = 0.01), preferred language (p < 0.05), insurance status (p = 0.001), and SSN status (p < 0.001). These factors may contribute to patient participation in retina-focused clinical trials. An awareness of these demographic and socioeconomic disparities may be valuable to consider when attempting to make clinical trial enrollment an equitable process for all patients, and strategies may be useful to help address these challenges.