The following is a guest post from Sandy Amaro, Head of Clinical Trial Diversity Center of Excellence, and Judy Sewards, Head of Clinical Trial Experience, at Pfizer, Inc.

Sandy Amaro
Sandy Amaro

The Importance of Clinical Trial Diversity

Race, ethnicity, culture, age, and gender are all factors that can impact patient outcomes, and different segments of the population can be disproportionately impacted by certain diseases. Because medicines and vaccines can work differently in different populations, diverse representation in clinical trials helps us better identify and research these differences in clinical outcomes. The more diverse our clinical trial participants are, the more we can learn about the safety and efficacy of a potential medicine or vaccine for individuals who have characteristics like those of the participants.

Ensuring diversity in clinical trials is also a matter of equity and reducing disparities in healthcare.  All individuals, regardless of background, should have the opportunity to participate and contribute to clinical research which could benefit them and their community. Yet, historically, many racial and ethnic groups have not been fully represented in clinical trials.  For example, Black Americans account for roughly 13% of the U.S. population1 but represented only 8% of clinical trial participants for the 53 newly approved drugs and biologics in 2020,2 according to the FDA’s Center for Drug Evaluation and Research.

Driving Progress, Together

Judy Sewards
Judy Sewards

There are barriers to clinical trial participation, some higher for communities of color. They include language barriers, distrust of medical researchers and the healthcare system, low levels of awareness and limited access to clinical trials. Many in the Black community still remember, or have heard of, the syphilis study conducted with Black men in Tuskegee, Alabama. The study ended 50 years ago, but the sentiments of betrayal and exploitation felt by many remains to this day. Overcoming these barriers won’t happen overnight, but we know the work that must be done.

We have seen progress over the past months by regulators and the industry at large. For example, in November 2020, the FDA issued its final Guidance, Enhancing the Diversity of Clinical Trial Populations – Eligibility Criteria, Enrollment Practices, and Trial Designs, with the aim of providing recommendations for how clinical trial sponsors can increase enrollment of underrepresented populations in their clinical trials3.  In addition, last year the Pharmaceutical Research and Manufacturers of America launched the first ever industry-wide principles on clinical trial diversity which will take effect in April 2021.4

Pfizer is fully committed to equity in clinical research, and we saw firsthand the importance of racial and ethnic representation in trials as we developed an investigational COVID-19 vaccine.  In turn, we have committed to design our clinical trials so that enrollment can reflect the racial and ethnic diversity of the countries where we conduct clinical trials and the epidemiology of the diseases we intend to treat or prevent.5

Some examples of how we are working to fulfill this commitment include: choosing investigative sites in communities that represent a diverse pool of potential participants and make it easier for people living in the community to participate; doing more to engage diverse clinical trial investigators and site staff; and working closely with our medical, government and patient advocacy partners, including the National Black Nurses Association, who are trusted voices and advisors for patients.  Also, a critical component of improving access to clinical trials is making it easier for people to find clinical trial information.  To help address this need, we recently launched which serves as a single destination for education and information on Pfizer clinical trials, learning more about how clinical trials work, and how to participate.

The Critical Role of Healthcare Providers

Participation in clinical trials is an important and personal choice.  However, a key issue that remains is that most people simply don’t know that participation in a trial is an option.  Today, there are 19 thousand clinical trials that are actively recruiting participants in the United States6 yet according to a 2017 Center for Information & Study on Clinical Research (CISCRP) survey only 14% of those who have never participated in a clinical trial are very confident they could find a clinical study that is right for them.7

An individual’s personal healthcare provider plays an important role in educating patients about clinical trials as an option that they may want to consider, and according to CISCRP, “discussions with my physician or specialist” is the preferred way to learn about clinical research.8

To hear more on the importance of clinical trial diversity from the NBNA’s President Dr. Martha Dawson and Pfizer’s Chief Development Officer, Dr Rod MacKenzie, click here: Ask A Pfizer Expert: Why Is Diversity In Clinical Trials Important? – YouTube.  And if you would like to learn more about specific clinical trials, you can visit:


  1. U.S. Census Bureau QuickFacts: United States
  2. 2020 Drug Trials Snapshots Summary Report (
  3. Enhancing the Diversity of Clinical Trial Populations — Eligibility Criteria, Enrollment Practices, and Trial Designs Guidance for Industry | FDA
  5. COVID-19 must catalyse changes to clinical development (
  6. Trends, Charts, and Maps –
  7. 2017-CISCRP-Perceptions-and-Insights-Study-Decision-Making-Process.pdf
  8. Charts & Statistics – Center for Information & Study on Clinical Research Participation (