**2. Evidence of disparity among racial/ethnic minorities**

The composition of minorities in clinical trials has historical been low. Between 1996 and 2002, blacks represented on average 9.3% of the total number of enrollees in cancer clinical trials [1]. That number peaked at 11% in 1996 and steadily declined to 7.9% in 2002 [1]. Similarly, Hispanics on average represented on average 3.1% of the total number of enrollees in cancer clinical trials between 1996 and 2002 [1]. Not only are minorities under-represented in clinical trials, but the overall racial and ethnic composition of clinical trials is not reported at an acceptable rate. Between 1990 and 2000, only 35.1% of treatment studies among cancer clinical trials reported race/ethnicity [2]. This number increased to 51.6% from 2001 thru 2010, but the percentage of blacks included in the analysis for the second decade decreased by 42% [2]. The lack of diversity goes beyond race and ethnicity. Similar trends are found in women, where they only represented 26.5% of the population in prevention studies between 2001 and 2010 [2].

The disparity in clinical trial participation is not limited to cancer clinical trials and the scientific impact can be significant in terms of outcomes. African Americans are disproportionately affected by hepatitis C virus (HCV) in the United States and HCV infection is the leading cause of cirrhosis and hepatocellular carcinoma and the most common indication for liver transplantation in the United States [3]. Although African Americans comprise approximately 13% of the US population, they make up approximately 23% of Americans with hepatitis C [4]. The rate of a positive HCV antibody test was higher in blacks than in whites (3.2% versus 1.5%) and black men had higher rates of infection, with the highest prevalence rate (9.8%) among black men ages 40–49 years [5, 6]. HCV treatment has undergone a rapid evolution in treatment with the first generation protease inhibitors released in 2011 and now multiple direct acting antivirals regimens with amazing outcomes [7, 8].

We performed a meta-analysis of clinical trials on hepatitis C treatment between January 2000 and December 2011 [9] to evaluate the participation of African Americans in hepatitis C clinical trials given the tremendous burden of that disease within this population. We reviewed 588 randomized controlled clinical trials on hepatitis C treatment with interferon 2a or 2b between January 2000 and December 2011. Of the 588 reviewed, 314 (53.4%) fit inclusion criteria [9]. This meta-analysis showed that of the 314 RCT's that met search criteria, only 123 (39.2%) actually reported race. We evaluated clinical trials in North American and Europe, and found significant differences. The clinical trials performed in North America were more likely to report racial data than European trials, although racial reporting overall increased over time in North America and Europe. Our main outcome was the rate of African American/ black participation in North American HCV clinical trials [10]. There was a statistically significant difference among the expected and observed participation of African Americans in HCV clinical trials in North America based on the prevalence of this disease within the population. The observed rate was 0.148 (95% CI, 0.126–0.174). Therefore, among those clinical trials reporting race, African Americans were significantly under-represented, especially given the disproportionate burden of hepatitis C within this population [9].
