The main finding of this study was that the majority of blood donors would be likely to participate in genetic studies and that less than 10% of donors would be less inclined to donate in the future if genetic studies were conducted in blood banks. Contrary to expectations, more donors indicated that they would be likely to participate in identity-linked research compared to identity-unlinked research. Finally, there was interest in the provision of genetic testing as a service at the blood center, although this scenario was accompanied by a higher potential for discouraging future donation.
Our main finding that the majority of blood donors expressed a willingness to participate in genetic research is consistent with the altruistic nature of blood donation and with some, but not all, of the findings from other populations. Among individuals who had previously participated in health research, actual consent rates for genetic studies have ranged from 21% to 85%.5
Researchers recently conducted an online survey of US adults, asking about their potential participation in a large cohort study examining genetic, environmental, and lifestyle factors. Sixty percent of participants indicated that they would participate in such a study.8
We observed some demographic and donation status differences in willingness to participate in genetic research. Older donors were more likely than younger donors to participate in identity-linked research; however, younger donors were more likely to participate in identity-unlinked research. In general, more frequent donors would be more likely to participate in future genetic studies. We suspect that more frequent donors have established a greater degree of trust with the blood bank that counterbalances concerns about confidentiality, resulting in a greater willingness to participate in even identity-linked genetic research.
While a previous study examining consent rates for genetic research reported lower consent rates among women,9
we did not detect any differences by sex. Non-Caucasian donors were less likely than Caucasian donors to indicate they would participate in genetic studies, although the difference was only significant for identity-unlinked research. In a recent review, Sterling and coworkers5
noted significantly lower participation rates among African Americans compared to Caucasians in several studies. In a National Health and Nutrition Examination Survey (NHANES) report, both females and non-Hispanic African Americans were less likely to consent to having their biologic samples stored in a national repository.9
In an NIH clinical center study, African Americans were less likely to permit future research, although 75% still authorized unlimited future research with their samples.10
On the other hand, Wendler and colleagues11
reviewed enrollment data from 20 health research studies and found little overall difference in participation rates between African Americans or Hispanics compared to non-Hispanic Caucasians. However, none of the studies of medical or surgical intervention reviewed by Wendler and colleagues included a primary genetic research question.
The finding of a greater acceptability of identity-linked versus unlinked research was unanticipated. We predicted that the better protection of confidentiality in the identity-unlinked scenario would be more attractive to donors. A possible explanation is that donors are interested in receiving the individual results of genetic research. This desire may temper privacy concerns that participants noted. Interestingly, in the survey of US adults about participation in a cohort study of genetic, environmental, and lifestyle factors, 75% of participants indicated they would be less inclined to participate if they did not receive research results.8
Others have noted greater than anticipated public interest in more public sharing of genetic information similar to the concept of the Personal Genome Project.12
The survey found that less than 10% of donors would be discouraged from donating if their blood center participated in genetic research and that more than 10% would be more likely to donate in the future. These results are encouraging, since donor loss is frequently mentioned by blood center personnel as a concern when genetic research is proposed. However, a donor loss of 8% to 9% without a concomitant increase in blood donation due to genetic research could be detrimental to blood banks. Under both identity-linked and -unlinked scenarios, donors aged 60 or older, non-Caucasian donors, and donors with less than a bachelor’s degree were more likely to be among this small group. We did not ask why donors would be less likely to donate in the future; however, we suspect that older donors view genetic studies as distracting from the blood center’s primary mission. In addition, comments on the questionnaire indicated that a few donors were unsure if participation in the study would be optional for blood donors, potentially contributing to the observed differences by level of education. In a previous study, we found that non-Caucasian donors had 30% to 40% lower odds of donating blood again within 1 year compared to Caucasian donors.13
This observation was also evident when we examined return after donor deferral regardless of first-time or repeat donor status.14
The racial disparity we observed in this study may be indicative of the larger pattern of lower repeat donation rates among non-Caucasian donors. Previously, we found that non-Caucasian donors were more likely than Caucasian donors to cite poor staff skills and bad treatment as factors influencing their decision not to donate blood in the future.15
Another study found that the race of the research physician, knowledge of the Tuskegee study, and belief that minorities bore most of the risks in medical research influenced African American subjects’ willingness to participate in medical research.16
These findings will have relevance to the design of future genetic studies in the blood donor setting, particularly in the design of educational and consent materials as well as staff training.
More than 70% of donors indicated that they would be interested in genetic testing as an optional service, with more than 80% of interested or undecided donors indicating that they would be interested in being tested for heart disease, colon cancer, and diabetes. However, more than 20% of participants indicated they would be less likely or much less likely to donate blood in the future if genetic testing was offered (as a service as opposed to research). During pilot test interviews, some donors indicated that genetic testing would make the donation process more complicated and introduce new processes. It is also possible that some participants did not understand that genetic testing would be optional rather than required for blood donation. Pilot test interviews indicated that even if the disease was not relevant to their personal health, some participants would be interested in being tested for genetic traits that may be passed to their children. Therefore, we specified that genetic testing could be for diseases the participant may develop or for diseases that the participant may pass on to their children. As a result, some men responded they would be interested in genetic testing for breast and ovarian cancer and some women indicated they would be interested in testing for prostate cancer.
There are limitations to our study. First, we used a convenience sample of predominantly repeat donors at one Northern California center who were willing to participate. Due to response bias, their opinions may not be representative of other blood donors at this center nor of all US blood donors. Questions were complex and required detailed descriptions of genetic studies, genetic testing, and linked or unlinked samples, so it is possible that some individuals, particularly those with less education, did not comprehend the scenarios presented. However, we conducted detailed pilot testing before our study to revise the instrument and maximize comprehension of the three scenarios. In addition, participants were highly educated, with more than 90% indicating that they at least had some college education. Another limitation is that donors were asked to indicate what they would do in a hypothetical scenario. However, we have previously found that donor intention to return is predictive of actual return.15
In conclusion, our study reveals that factors about the research study design, such as whether samples are linked to donor information, as well as donor demographics and donation status, will impact donor consent rates in genetic studies. The finding that the majority of donors would be interested in participating in genetic studies is encouraging with regard to the feasibility of conducting genetic research in the blood bank setting. However, donor loss due to genetic research in the blood bank remains a potential concern. Therefore, we suggest that if genetic research is implemented in blood banks, studies should be implemented slowly and actual participation and refusal rates as well as subsequent donation trends should be monitored.