Under-enrolling minority patients in clinical trials reduces generalizability. CLEAR III, a randomized controlled trial, presented an opportunity to assess African American (AA) participation.AA enrollment was compared to U.S. population and NINDS trial data then stratified by region; census data for 42 recruitment cities were compared to screening and randomization percentages, using simple linear regression.AAs were 25% of screens and 45.1% of enrollments (n=370), more than twice the 19.8% participation rate reported by the 2011 NINDS Advisory Panel on Health Disparities Research and triple the projected 13.9% 2014 U.S. population. Conversion rates were (AA vs. non-AA): overall (8.7% vs. 3.4%, p0.001); Northeast (7.7% vs. 2.9%, p0.001); South (8.2% vs. 4.0%, p0.001); Midwest (10.3% vs. 3.6%, p0.01); and West (8.9% vs. 3.8%, p=0.02). AA enrollments ranged from 0% to 100% (mean: 40.4%). AA screening ranged from 0% to 63.7% (mean: 23.2%). AA city census ranged from 1.3% to 82.7% (mean: 28.0%); higher census was associated with higher screening (p0.0001) and enrollment (p=0.004).AAs were willing to enroll in an acute stroke trial. AA city census rates should be considered when selecting enrollment centers and setting recruitment goals. Factors leading to successful AA recruitment should be further investigated, as population-based participation is a goal in all trials.
