Clinical trials (also called medical research and research studies) are used to determine whether new drugs/treatments are both safe and effective. In addition, they help researchers decide if a drug’s risks are worth its benefits (risk/benefit ratio). The Food and Drug Administration (FDA) considers the results from clinical trials in approving a drug or treatment. Once approved, the therapy becomes available for doctors to prescribe to their patients.

New therapies are tested on people in clinical trials only after laboratory and animal studies show promising results. It is a challenge for researchers to recruit adequate numbers of clinical trial participants, and even more of a challenge to recruit Black Americans. This is a concern because there is evidence that certain drugs have different effects on Black Americans than they do on Caucasians.

To help garner trust and understanding, here are five questions frequently asked by Black Americans around clinical trials, answered.

Why don’t more Black Americans participate in clinical trials?

There is a general distrust of the medical/healthcare system amongst some Black Americans, and perhaps many, based on personal experience. In addition, historical events have given Black Americans reason to mistrust clinical trials.

On July 26, 1972, the New York Times reported on what it called the “longest-running non-therapeutic experiment on human beings in medical history.” Departing from their Hippocratic oath to “First, do no harm,” physicians from the U.S. Public Health Service allowed nearly 400 poor, Black sharecroppers with syphilis to go untreated for forty years. These men from Macon County, Alabama were told they were being treated for “bad blood.” However, they were all part of the Tuskegee Experiment, which was designed to study the progression of syphilis—a potentially fatal sexually transmitted infection.

Many health professionals and leaders in the Black community cite the Tuskegee Experiment as a factor contributing to low participation of Black Americans in routine preventive care, clinical trials, and organ donation. However, we can be thankful that the Tuskegee Experiment did lead to a change for the better in how medical research is done.

How can a person be sure that a clinical trial is safe?

An Institutional Review Board (IRB) must approve all studies involving human or animal subjects in advance. Complaints should be addressed to the director of the study or the institution’s IRB.

Institutional Review Boards (IRB) are made up of physicians, ethicists, religious leaders and other community leaders, and are required to look at studies that are going to use human or animal subjects.

An IRB’s main responsibility is to protect the public from harm and look carefully at each study’s methods to make sure the research is done in an ethical way.

Does drug effectiveness vary across races?

Yes, there are many therapies to which Black Americans are known to respond differently than whites. For example, some drugs are less effective in Black Americans (such as beta blockers for hypertension), some cause increased adverse events (such as the occurrence of angioedema with the use of ACE inhibitors), and some show both types of differences.

One study showed that although ACE inhibitors are particularly effective in whites, but not Black Americans, a combination of hydralazine plus isosorbide dinitrate reduced the mortality of Black patients. At the same time, white patients given this combination of drugs showed no difference from placebo (sugar pill). The study concluded that clinical trials involving large numbers of Black patients are needed to clarify their response to therapy further.

Another study compared enalapril therapy for heart failure among blacks and whites. Enalapril therapy reduced the risk of hospitalization for heart failure among white patients with left ventricular dysfunction, but not among similar Black patients. Again, the researchers concluded that their findings underscored the need for additional research on the efficacy of therapies for heart failure in black patients.

How can I participate in a clinical trial?

To participate in a clinical trial, ask your health care provider or look up trials relevant to your condition at clinicaltrials.gov.

Not all studies involve drugs; some long-term studies will only ask you to have a physical and fill out some paperwork every few years. Other studies need “controls”-people who don’t receive the treatment so the results of those receiving treatment can be compared with them. You have the right to quit any study you become involved in at any time.