The Importance of Diversity in Clinical Trials

In the world of clinical trials, uniformity can be a dirty word. From blind use of placebos to dosage variation, incorporation of variables is an essential part of any study. But it’s important for researchers to ensure variety not just in the drugs being tested, but among patients as well. A lack of diversity can lead to skewed data, and some in the medical community are concerned that studies are not recruiting from a wide enough array of demographics.

The FDA is calling for stronger efforts to engage underrepresented populations in clinical trials1. And the University of Kansas has launched an investigation into how to promote a better understanding of clinical trials among those populations in order to increase participation2.

Who Is Underrepresented and Why Does It Matter?

According to the FDA, the least common participants in clinical trials are elderly people and ethnic or racial minorities. Forbes reports that African Americans, for example, while making up 12 percent of the general U.S. population, comprise only 5 percent of all clinical trial participants3.

As for why this disparity exists, the University of Kansas, after a series of focus groups and interviews, chalks much of it up to unawareness of the purpose, or even the existence, of clinical trials. Many people in minority communities and rural areas are misinformed, or insufficiently informed, by doctors and the media, and are thus unaware that clinical trials are a treatment option.

It is crucial that the research community overcome this hurdle. Genetic differences among people from different racial or ethnic backgrounds often lead to different responses to certain medications. The National Medical Association notes that someone of African descent may respond to a drug differently than someone of Hispanic or Asian descent4. Recruiting a diverse body of participants to a clinical trial helps researchers cover all bases, making sure no demographic-specific side effect of a given medication is overlooked.

Obstacles to Diversity

Maximizing diversity in a clinical trial may be easier said than done. Researchers hoping to recruit patients from all walks of life may run up against systemic obstacles. One such obstacle deals with the nature of early-phase studies. Phase I studies typically recruit no more than 80 patients, and it may be difficult to fit enough people from a wide array of demographics under that ceiling.

Then there’s the cost of participation, which can be more prohibitive for some demographics than others. For example, Medicare will not necessarily cover the treatment administered in a clinical trial, passing the cost of that treatment on to the patient. Many sponsors provide the treatment in a trial at no cost to the patient, but when they don’t, elderly would-be participants receiving Medicare may be disincentivized from enrolling in a trial.

Before a drug is brought to market for the general population, it is essential that it be tested on as many subsets of that population as possible. And if this goal is to be achieved, researchers will have to reckon with significant institutional and socioeconomic factors.

Decentralizing clinical trials is one way to increase patient diversity in your clinical studies. By reducing the patient burden, and moving to a remote setting, you can expand your patient outreach, thus expanding diversity. 

1 Califf, Robert; 2016: The Year of  Diversity in Clinical Trials; FDA Voice (; 1/27/16

2 Krings, Mike; KU leading study to learn about minority perceptions of cancer clinical trials; The University of Kansas; 2/23/16

3 Lechleiter, John; Closing The Diversity Gap In Clinical Trials; Forbes Magazine; 4/9/14

4 Burroughs, Valentine J.; Maxey, Randall W.; Levy, Richard A.; Racial and ethnic differences in responses to medicines: towards individualized pharmaceutical treatment; Journal of the National Medical Association; October 2002

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