Investigator Racial Diversity and Clinical Trial Participation

Last registered on September 18, 2023

Pre-Trial

Trial Information

General Information

Title
Investigator Racial Diversity and Clinical Trial Participation
RCT ID
AEARCTR-0011926
Initial registration date
August 15, 2023

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
August 16, 2023, 11:52 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Last updated
September 18, 2023, 2:49 PM EDT

Last updated is the most recent time when changes to the trial's registration were published.

Locations

Region

Primary Investigator

Affiliation
Harvard University

Other Primary Investigator(s)

PI Affiliation
Universitat Pompeu Fabra
PI Affiliation
Harvard University
PI Affiliation
Northwestern Memorial Hospital

Additional Trial Information

Status
Completed
Start date
2021-06-04
End date
2022-02-21
Secondary IDs
ClinicalTrials.gov: NCT04938895
Prior work
This trial is based on or builds upon one or more prior RCTs.
Abstract
Participation of Black patients in clinical trials remains low relative to population and disease-burden benchmarks. We investigate whether increased racial diversity of trial principal investigators could increase enrollment of Black patients. To do so, we conducted a survey experiment in which respondents were shown a photo of a current NIH investigator in which race (Black/White) was cross-randomized as was gender (male/female) to provide a relevant benchmark. Black respondents reported 10.5 percent higher interest in participating in a clinical study led by a race concordant investigator. Gender concordance had no effect. Multivariate regression analyses point to perceived trustworthiness as the most important factor in explaining the pattern of results. Our findings suggest that increasing the racial diversity of clinical trial investigators is a potentially effective method for encouraging enrollment of Black participants in medical research.

*Please see ClinicalTrials.gov NCT04938895 for more information and pre-registration.

Registration Citation

Citation
Alsan, Marcella et al. 2023. "Investigator Racial Diversity and Clinical Trial Participation." AEA RCT Registry. September 18. https://doi.org/10.1257/rct.11926-1.1
Experimental Details

Interventions

Intervention(s)
We plan to recruit subjects and randomly assign them to one of four treatments. In each treatment arm, the subject will view a photograph of a real NIH investigator. We experimentally vary treatment along two dimensions: whether the sender is Black or white and whether the sender is male or female.
Intervention (Hidden)
Subjects were randomly assigned to one of four treatments. In each treatment arm, the subject viewed a photograph of a real NIH investigator. We experimentally vary treatment along two dimensions: whether the sender is Black or white and whether the sender is male or female. We survey participants' willingness to participate in a clinical trial and how their initial response is impacted by other characteristics such as perceived trustworthiness and quality.
Intervention Start Date
2022-02-17
Intervention End Date
2022-02-19

Primary Outcomes

Primary Outcomes (end points)
Willingness to Participate in a Clinical Trial
Primary Outcomes (explanation)
Survey respondents' willingness to participate in a clinical trial led by the person in the photo

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We plan to recruit subjects and randomly assign them to one of four treatments. In each treatment arm, the subject will view a photograph of a real NIH investigator. We experimentally vary treatment along two dimensions: whether the sender is Black or white and whether the sender is male or female.

Our primary aim is to assess whether the subject's stated willingness to participate in a clinical trial led by the investigator. Our secondary aim is to assess whether the subject is a more objective measure of interest in signing up for information on other clinical trials. To assess mechanisms, we will ask the respondent to rate the subject's perceived trustworthiness and quality of the investigator. In addition, we will also assess the subject's perceived attractiveness and age of the investigator as well as the subject's risk aversion, altruism, time preference, and general trust.
Experimental Design Details
Randomization Method
Randomization was computer-generated and performed using Qualtrics’ own functionality.
Randomization Unit
Individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
412
Sample size: planned number of observations
412
Sample size (or number of clusters) by treatment arms
80 subjects in Black Woman Investigator arm, 81 subjects in Black Man Investigator arm, 78 subjects in White Woman Investigator arm, 84 subjects in White Man Investigator arm.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB

Institutional Review Boards (IRBs)

IRB Name
Harvard University Institutional Review Board
IRB Approval Date
2021-07-07
IRB Approval Number
IRB21-0864

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials