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Title: Factors influencing enrollment of African Americans in the Look AHEAD trial

Author
item MOUNT, DAVID - Wake Forest School Of Medicine
item DAVIS, CRALEN - Wake Forest School Of Medicine
item KENNEDY, BETTY - Louisiana School Boards Association
item RAATZ, SUSAN - University Of Minnesota
item DOTSON, KATHY - Wake Forest School Of Medicine
item GARY-WEBB, TIFFANY - Columbia University - New York
item THOMAS, SHEIKILYA - University Of Alabama
item JOHNSON, KAREN - University Of Tennessee
item ESPELAND, MARK - Wake Forest School Of Medicine
item FOREYT, JOHN - Children'S Nutrition Research Center (CNRC)

Submitted to: Clinical Trials
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2012
Publication Date: 2/1/2012
Citation: Mount, D.L., Davis, C., Kennedy, B., Raatz, S., Dotson, K., Gary-Webb, T.L., Thomas, S., Johnson, K.C., Espeland, M.A., Look AHEAD Research Group. 2012. Factors influencing enrollment of African Americans in the Look AHEAD trial. Clinical Trials. 9(1):80-89.

Interpretive Summary: The recruitment of African-Americans into clinical research trials is impacted and influenced by many different eligibility criteria, some of which may disqualify African-American subjects more so than other volunteers. Using the Look AHEAD trial, we tried to determine if African-Americans are prone to any conditions that may disqualify them from the study based on eligibility criteria and therefore be under represented in trial data. Different possible reasons between screening, eligibility, and enrollment rates were examined for African-Americans and members of other racial and ethnic groups. The study found that African-Americans were just as likely to be ineligible for the study as other groups due to inability to meet follow-up or refused to attend clinic visits. Furthermore, the enrollment rates of subjects with a history of cardiovascular disease and diabetes was the same across all ethnic groups. African-Americans were found to have higher adverse levels of blood pressure, heart rate, serum creatine, and other blood markers which excluded them from being enrolled in the study. Due to this, African-American subjects were more often ineligible for the Look AHEAD trial due the presence of comorbid conditions. In the future, however, trial eligibility criteria may need to be modified for the impact of these different factors to ensure greater yields of often excluded and under represented populations.

Technical Abstract: Many factors have been identified that influence the recruitment of African Americans into clinical trials; however, the influence of eligibility criteria may not be widely appreciated. We used the experience from the Look AHEAD (Action for Health in Diabetes) trial screening process to examine the differential impact eligibility criteria had on the enrollment of African Americans compared to other volunteers. Look AHEAD is a large randomized clinical trial to examine whether assignment to an intensive lifestyle intervention designed to produce and maintain weight loss reduces the long-term risk of major cardiovascular events in adults with type 2 diabetes. Differences in the screening, eligibility, and enrollment rates between African Americans and members of other racial/ethnic groups were examined to identify possible reasons. Look AHEAD screened 28,735 individuals for enrollment, including 6226 (21.7%) who were self-identified African Americans. Of these volunteers, 12.9% of the African Americans compared to 19.3% of all other screenees ultimately enrolled (p < 0.001). African Americans no more often than others were lost to follow-up or refused to attend clinic visits to establish eligibility. Furthermore, the enrollment rates of individuals with histories of cardiovascular disease and diabetes therapy did not markedly differ between the ethnic groups. Higher prevalence of adverse levels of blood pressure, heart rate, HbA1c, and serum creatinine among African American screenees accounted for the greater proportions excluded (all p < 0.001). Compared to non-African Americans, African American were more often ineligible for the Look AHEAD trial due to comorbid conditions. Monitoring trial eligibility criteria for differential impact, and modifying them when appropriate, may ensure greater enrollment yields.