The mistreatment and persistent exclusion of ethnic minorities, women, and other underrepresented groups from drug trials is a well-documented issue. In 2020, of the 32,000 individuals who participated in new American drug trials, key demographic groups were persistently underrepresented: only 8% were Black, 6% were Asian, and 11% were Hispanic.
Underrepresented racial and ethnic minority groups often carry a high burden of chronic diseases, which represent a large proportion of efforts in current drug research and development. For example, the highest rate of asthma is found in Puerto Rican Americans and Black youths. A similar trend exists for type 1 diabetes, with a higher incidence among ethnic minorities compared to the white population. These disparities in disease incidence across demographic groups are further compounded by the underrepresented groups’ inadequate access to health insurance and higher incidence of poverty.
One major barrier to diversity in clinical trials is the lack of standardization. Though the Food and Drug Administration (FDA) continually encourages diversity in clinical trials, it fails to set quotas or guidelines mandating representation. The Federal Food, Drug and Cosmetic Act of the Food and Drug Omnibus Reform Act has begun mandating Diversity Action Plans, which ask researchers to specify demographic enrollment goals and the rationale for all enrollment criteria. However, enforcing the diversity plan requirement for trials that do not meet the ambiguous enrollment goals but cannot be waived from the requirement will be difficult. Additionally, the Diversity Action Plans requirement does not apply to all studies or trials.
Logistical barriers further exacerbate the problem. Many clinical trials are concentrated in high-income academic medical centers, so low-income groups tend to face long transportation times and high costs attempting to visit such centers. A study from 2015 found that patients with an annual income below $50,000 were 32% less likely to participate in a cancer clinical trial than patients with income levels above this threshold.
Additionally, clinical trials often require individuals to find time off work and pay for child care, reinforcing preexisting financial barriers to participation. The exclusion of participants from clinical trials based on the presence of preexisting health conditions further disadvantages minority populations. Patients of color are more likely to have other comorbidities, such as hypertension and diabetes — factors that preclude their participation in clinical trials because clinicians are looking for patients with few other health conditions.
However, the lack of representation is more nuanced than simple exclusion. A historic lack of informed consent and unethical practice during clinical trials has bred mistrust among some demographics. Many historical clinical trials and medicinal practices were defined by their mistreatment of participants, often the poorer minority groups of the time. The Tuskegee syphilis study, which followed the natural history of syphilis in black males, denied participants treatment when it became available. The “Mississippi Appendectomy” refers to the practice of involuntary hysterectomies in the 1920’s to 1970’s that resulted in sterilization for thousands of women, particularly black women.
Mistrust is augmented by a lack of literacy associated with the way that clinical trials function and the requirements they involve. A survey about public attitudes towards participation in clinical trials indicated that one of the biggest barriers to participation was safety concerns and a lack of awareness about the regulations governing clinical trials. Nearly 90% of adults in the United States struggle with health literacy in general, further decreasing engagement between patients and the larger healthcare community.
Combating the myriad of causes for disparities in the demographics for clinical trials requires a multifaceted approach. All trials should begin by defining a representative population, a place where the FDA’s diversity action plans can help. Diseases that disproportionately affect certain populations require clinical trials that feature a larger proportion of individuals from that demographic background. Clinicians can further collect data from an specific cross-section of the population through the patient registry, which holds a wealth of information on hundreds of thousands of patients from diverse backgrounds.
Finally, improving healthcare literacy through the use of informative fact sheets and focusing literacy efforts on rural or low-income populations could help adequately educate patients on the benefits and risks of clinical trials; improved healthcare literacy could also help patients become more aware of clinical trials in general, increasing the likelihood that a sick patient from a disadvantaged community participates in a clinical trial.
