Submitted to: Clinical Trials
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2006
Publication Date: 10/1/2006
Citation: Espeland, M.A., Dotson, K., Jaramillo, S.A., Kahn, S.E., Harrison, B., Montez, M., Foreyt, J.P., Montgomery, B., Knowler, W.C. 2006. Consent for genetics studies among clinical trial participants: Findings from Action for Health in Diabetes (Look AHEAD). Clinical Trials. 3(5):443-456. Interpretive Summary: This article describes the experience in obtaining consent for DNA testing from participants in the Action for Health and Diabetes (Look Ahead) clinical trial. Genetic specimens can increase the value of clinical trials by enabling correlations between genes and disease to be studied. The willingness to consent to DNA testing was 89.7%; this was a greater percentage than several other cohort studies have reported. The authors suggest that the high rate of consent may be due to the rapport established between the study staff and potential participants through the extensive screening process. Rates of consent were lower among African-American and Hispanic participants than among White and Asian participants. Those without a history of cardiovascular disease and those without high cholesterol were also less likely to consent. Contrary to other studies, women and the highly educated were less likely to consent. The authors suggest more studies need to be done to determine which features of the consent process were of concern to the women and the highly educated of the cohort. It is important to consider the fact that the varying rates of consent among groups of subjects may introduce biases in estimates of genetic relationships. Researchers must develop analytical methods that address the potential ramifications of non-consent.
Technical Abstract: Increasingly, genetic specimens are collected to expand the value of clinical trials through study of genetic effects on disease incidence, progression or response to interventions. We describe the experience obtaining IRB-approved DNA consent forms across the 19 institutions in the Action for Health in Diabetes (Look AHEAD), a clinical trial examining the effect of a lifestyle intervention for weight loss on the risk of serious cardiovascular events among individuals with type 2 diabetes. We document the rates participants provided consent for DNA research, identify participant characteristics associated with consent, and discuss implications for genetics research. IRB approval to participate was obtained from 17 of 19 institutions. The overall rate of consent was 89.6% among the 15 institutions that had completed consenting at the time of our analysis, which was higher than reported for other types of cohort studies. Consent rates were associated with factors expected to be associated with weight loss and cardiovascular disease and to affect the distribution of candidate genes. Non-consent occurred more frequently among participants grouped as African-American, Hispanic, female, more highly educated or not dyslipidemic. The generalizabilty of results is limited by the inclusion/exclusion criteria of the trial. Barriers to obtaining consent to participate in genetic studies may differ from other recruitment settings. Because of the potentially complex associations between personal characteristics related to adherence, outcomes and gene distributions, differential rates of consent may introduce biases in estimates of genetic relationships.