Clinical trial enrollment can vary based on demographics. Cancer drug trials, for example, have been shown to skew disproportionately toward young, White, male participants. Variability also exists in a treatment’s effectiveness across different demographic groups. Similarly, many medications have meaningful pharmacological differences based on sex and race.
 
Gaps in the amount of trial data collected for a demographic group could lead to that group receiving treatments that were developed on a knowledge base that was not completely applicable. This means that disparities in trial enrollment could result in disparities in the quality of care available in the future as treatments are recommended, prescribed, and used on the basis of imperfect information for understudied populations.
 
A broad accounting of how frequently demographics are publicly reported—and how those demographics vary across clinical trials—is missing from the current literature and related discussion. This report seeks to fill that gap by quantifying the number of studies with and without demographic information (sex, ethnicity, or race). For studies that include demographic information, we investigate how the demographic distributions vary across studies and compare these distributions to the general population. This provides a baseline for where the sector currently stands and context for future changes in demographic reporting and balance.