Informed Consent for Biorepositories: Assessing Prospective Participants' Understanding and Opinions

Biorepositories are an invaluable resource for basic, epidemiologic, and translational research. The application of molecular technologies to collections of human biological specimens represents an unparalleled opportunity to discover new ways to prevent, diagnose, and treat cancer and other diseases (1). Efforts to compile health information and collect biological specimens from large populations are already under way in the United States and around the world (2), with the ultimate goal of unlocking the genomic basis of disease and ushering in an era of personalized medicine (3). Such achievements, however, depend on the ready availability of high-quality specimens, annotated with relevant clinical data and collected with scrupulous attention to ethical, legal, and social concerns. In particular, issues related to informed consent are among the most pressing in human biospecimens research (4, 5). In addition to questions about when informed consent must be obtained, there is considerable debate about what information and options should be incorporated into the consent process (6-10).

Several previous studies from the United States have focused on attitudes among persons who had already contributed tissue for research (11-15); others involved population-based surveys of specific groups regarding use of stored tissue for research and the need for consent (16-20). Still, questions remain: how can the collection, storage, and future research use of specimens and data be described so that prospective participants can make informed decisions? What do prospective participants think about controversial aspects of biorepositories, such as indefinite storage, links to medical records, future contact, development of commercial products, access to research results, and the ability to withdraw? What effect do these issues have on the willingness of potential subjects to participate?

We sought to gather input on a consent template developed for the Duke Biorepository from individuals generally representative of those who might one day consider contributing specimens. Specifically, we conducted cognitive interviews to explore the following questions: (a) how do prospective participants understand or interpret the information conveyed in the consent template, and (b) what are their opinions about the information conveyed?

The Duke Biorepository consent template was developed based on federal regulations (21, 22) and best practice guidelines (4, 23-26), as well as guidance from the Duke University Health System Institutional Review Board (27) and publicly available sample forms from other institutions. It was further revised following input from senior Duke investigators. For the purposes of our study, we developed a cognitive interview (28) protocol about the template, based on a review of literature regarding informed consent and attitudes toward biobanking and research using stored tissue. The interview focused on participants' comprehension and opinions, and the decisions they would make if asked to participate in the Biorepository. The research was determined by the Duke and RTI Institutional Review Boards to be exempt from review (45CFR46.101[b][2]).

We recruited interview participants from the Durham, NC area, using newspaper advertisements, Internet postings, and flyers placed in Duke clinics and in several community locations. Respondents were screened by telephone and selected to oversample minorities and people with lower educational attainment, to achieve diversity by age and sex, and to avoid habitual research participants. A sample of 40 participants was expected to achieve saturation (i.e., no additional insights gained from further interviews). The purpose of cognitive interviewing is not statistical estimation; thus, sample sizes are not selected to supply statistical power for hypothesis testing. The goal is to maximize the diversity of the sample and to attain insights by interviewing a variety of individuals who will be useful in informing the issue (28, 29).

Interviews took place from May to October 2007. We used an iterative approach, revising the template and the interview questions based on feedback gathered in each of four rounds of interviews. Participants were interviewed in person by one of two professional interviewers at RTI's Laboratory for Survey Methods and Measurement. Participants first completed a brief written survey that collected basic demographic information, as well as answers to four validated questions intended to assess trust in medical researchers (30). Interviews were conducted by non–Duke personnel in a nonclinical setting in part to avoid biasing the response to these questions. After reading the entire consent template (Appendix A), participants were interviewed (script available upon request). All interviews were digitally recorded and lasted an average of 30 min. Participants gave oral consent and received $40 for participating.

Interviews were analyzed using standard inductive qualitative methods (31, 32). One author (E. Dean), who conducted most of the interviews, compiled a detailed report based on interview notes and recordings. She characterized the nature of interviewee responses to questions, wherever applicable, as positive/comfortable, mixed/neutral, or negative, and also itemized reasons interviewees gave for their responses. The other author (L.M. Beskow) listened to all recordings and independently characterized the nature of interviewee responses. She also categorized interviewees' reasoning using content codes initially developed based on expert knowledge of the field, and refined over the course of listening to the interviews to ensure the integrity of the categories identified and to ascertain that no new categories were emerging during the interview process. Findings were then reconciled by both authors. Fisher's exact test, a test specifically intended for small sample sizes, was used to make preliminary quantitative comparisons of responses to the brief written survey using STATA version 8.0 (StataCorp LP).

The study sample was demographically diverse (Table 1). Responses to the four survey questions assessing trust in medical researchers revealed varying degrees of trust (Fig. 1), although overall, responses tended to indicate neutral feelings or some level of trust, rather than distrust. In this sample, trust did not differ by age, sex, race, education, research experience, or status as a Duke patient, with one exception. Most (75%) interviewees either strongly or somewhat agreed with the statement, “Doctors who do medical research care only about what is best for each patient.” There were, however, differences by research experience: 33% of those who had participated in research in the past year disagreed with this statement, compared with only 3% of those who had not (P = 0.05).

When asked to describe what the consent form was asking them to do, all but two interviewees mentioned “research,” and nearly three quarters correctly mentioned the concept of “leftover blood.” Interviewees typically described a biorepository as a place where blood is stored and studied. As one stated: “It's kind of like a blood bank except that it's not for people who need blood to live, it's for people who need blood to study” (ID 22).

When asked what kinds of research they thought would be conducted, more than half of the interviewees mentioned research on specific conditions. Cancer, diabetes, heart disease, Alzheimer disease, and hypertension were most frequently cited; other examples included asthma, bird flu, HIV-AIDS, and obesity. Half described research involving DNA or genes. Some mentioned general concepts, such as “developing new drugs” and “things you could find out by testing blood.”

Later rounds of interviews included the question, “How would you feel if this consent form were asking you to have your blood drawn just to give to the Biorepository?” Among 22 interviewees asked this question, half said it would pose no problem. Others expressed concerns that included dislike of needles, lack of personal benefit, lack of association with their personal physician, lack of association with a specific study, and inconvenience (Table 2).

Almost three quarters of interviewees thought their blood would be kept as long as it was needed, or forever. The remainder generally knew that the consent form made reference to indefinite storage, but had doubts about how long their blood would actually last. About half of these were unsure how long it would last; the other half gave estimates ranging from 3 months to “25 to 100 years.”

When interviewees were asked how they felt about indefinite storage, more than two thirds reported feeling either positive or comfortable (Table 2). Some cited the option to withdraw or to not participate as the reason they were comfortable. Reservations expressed by those less comfortable included concern for their descendents and unforeseen events at the Biorepository.

Nearly three quarters of interviewees correctly thought they would be contacted once per year to update basic information. When asked what frequency would be reasonable, over half said once per year and about a third said more than once per year, with answers ranging from two to six times per year. Other answers included “one time only,” “never,” and “it depends on the length of the interview.”

Almost all interviewees thought that personal medical information (e.g., test results, diagnoses, medications, procedures, and biometric data) would be collected from their medical record. Approximately one third mentioned family history information, and several mentioned other kinds of information, such as race, lifestyle information, and health insurance status. A few were unsure what kinds of information would be collected.

More than half of interviewees said that providing access to their medical record would not affect their decision about participating, citing reasons such as altruism and lack of concern about risks (Table 2). Others, however, expressed concerns about confidentiality, changes in health status, and uncertainties about what information would be collected and how it would be used.

In later interviews, those who expressed discomfort about medical record access were asked, “Are there any ways the Biorepository's procedures could be revised to make you more comfortable?” Among 10 interviewees asked this question, 6 said they wanted to be asked permission each time. One wanted an “iron-clad guarantee” of confidentiality, one wanted to know exactly what was being studied, one wanted to designate certain parts of her medical record “off limits,” and one said there were no circumstances under which she would agree to ongoing access.

When interviewees were asked what kinds of things would cause them to change their minds about participating, a breach of security or a scandal were the most frequently cited reasons:

Other common reasons included negative news stories about research in general, changes in health status, excessive or burdensome contact from researchers, and negative responses from peers (Table 2).

We asked interviewees about the statement that “researchers from other universities (other than Duke), the government, and drug or health-related companies” could apply to study materials stored in the Biorepository. Nearly three fourths were comfortable with the idea of other academic researchers having access to the Biorepository. Frequent themes included “strength in numbers” (i.e., allowing other academic researchers access could amplify research benefits), shared goals among researchers, and putting materials to “good use” (Table 3). Interviewees who expressed concerns mentioned issues such as the prestige of the university, whether universities outside the United States would have access, and lack of control over research use.

More than half of the interviewees were concerned about government researchers having access to the Biorepository. Several made reference to “Big Brother.” Other common themes included misuse of information and government intrusion into private areas (Table 3). Among those comfortable with government researchers, a common refrain was “research is research,” no matter who is doing it.

More than half of the interviewees were either positive or comfortable regarding health care industry access to the Biorepository (Table 3). Profit motive was mentioned both favorably and unfavorably; for example, one person seemed more comfortable with the idea of profit-driven research than with research purely for the sake of inquiry, whereas others expressed reservations about the motivations of for-profit researchers.

Almost three fourths of interviewees were comfortable with being contacted about additional research. Most correctly believed they might be contacted once or twice a year; most also considered this a reasonable frequency. One cited the possibility of opting out of any proposed research as a reason for feeling comfortable about such contact. Concerns included excessive contact and lack of personal benefit (Table 3).

When interviewees were asked what they thought additional research would involve, common responses included giving more blood, participating in a survey or interview, and participating in a clinical trial. However, the most frequent answer was related to selection criteria: more than one fourth of interviewees thought they would be contacted because of something that had been found in their blood. One person, for instance, said, “I can't imagine they would contact me unless they saw something in my blood that interested them and they needed more, needed to know more” (ID 13). Some who expressed this belief felt positively about the prospect of research contact, although others felt negatively:

When asked about risks involved in participating in the Biorepository, most interviewees mentioned loss of privacy or confidentiality. Other concerns included technological advances that might expand the scope of research, loss of control (potentially affecting family members), and lack of knowledge about what uses were being made of specimens (Table 3).

Approximately one fourth of interviewees thought there were no risks involved. Interviewees who mentioned at least one risk were asked, “How important or how much of a concern are these risks to you?” About one third considered the risks to be very important (Table 3). One asked whether there were legal penalties or financial recourse for breaches of confidentiality; another felt that no matter how many precautions were taken, “The bottom line is the trust you put in people to keep their mouths closed and do the right thing. That's all you can do” (ID 11).

About one third of interviewees believed the risks were not important, citing reasons such as researcher self-interest, age, and trust in the research enterprise (Table 3). One person said she was not concerned because “Who would really want to know that stuff? Even if they saw it, unless they're a doctor or a researcher, they wouldn't even know what it was” (ID 13).

No interviewees expected direct benefit, although a few mentioned the possibility of long-term benefit resulting from research done on their biospecimens, and more than three fourths mentioned altruism and/or social benefit (Table 3).

About a third of interviewees felt positively about the prospect that commercial products could be developed through biorepository research; another third were comfortable with the idea (Table 4). About one fifth, however, responded negatively to the idea of others profiting from their specimens or data.

When asked about the statement “You should not expect to share in any of the profits,” comments from about two thirds of interviewees suggested they were comfortable. Common themes were the large number of subjects participating, lack of prior expectations, and the fact that the actual work would be done by researchers (Table 4). One interviewee was specifically positive about not receiving a profit share because of confidentiality concerns.

Among those uncomfortable with the statement, a few thought participants should share in profits (Table 4). Most, however, still said a profit share was not expected, and others expressed a desire for more benefit sharing at a societal level. Some interviewees expressed dislike for the presence of the statement itself in the consent form. One thought it “sounds selfish” (ID 17); another, who did not expect a profit share, stated:

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Nearly two thirds of interviewees were comfortable with the statement, “You should not expect to get individual results from research done with your blood.” Common themes were acknowledgment of limited research resources, differences in research versus medical care, and lack of prior expectations for receiving individual results (Table 4). Some interviewees thought their physician would already know about any problems with their health, and one expressed concern that disclosing ambiguous research findings might create additional problems.

The remaining third of interviewees expressed concerns about not getting individual results, citing a desire for reciprocity for having rendered assistance, and a desire to be contacted if the findings had clinical relevance (Table 4). One person disliked the tone of the statement itself: “I would still participate, but I think they could have made that statement sound a little nicer” (ID 32).

After the first round of interviews, we added the question, “If researchers discovered something serious about your health, do you think they should let you know about it?” Among 30 interviewees asked this question, over three fourths said “yes.” Reasons for doing so included reciprocity, “common courtesy,” clinical utility, and the possibility of access to potentially beneficial new medical knowledge (Table 4).

Nearly half of the interviewees thought it would be very important to receive general news about studies being done through the Biorepository. Several thought it would be beneficial or would constitute a fair exchange for having volunteered for a study (Table 4). Many thought it important to determine whether their samples were being put to good use; for example:

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Of the remaining interviewees, about half said access to general news was somewhat important; half said it was not important.

Most (85%) interviewees said that, if asked, they would allow their blood and information to be stored indefinitely at the Biorepository for use in future research (Table 5). Among the six interviewees who declined or were unsure, privacy concerns were a major factor; five of the six had characterized the risks involved as “very important.”

In this sample, there were no differences in responses to the consent statements based on demographic characteristics or on answers to the survey questions about trust in medical researchers, except for the following.

Someone from the Biorepository can contact me once a year to update my information. Most (78%) interviewees indicated that they would say “yes” to this statement. There were, however, differences by trust in medical researchers: 100% of those who disagreed with the statement “Doctors who do medical research care only about what is best for each patient” said “no” or were unsure about update contact, compared with only 16% of those who had agreed or were neutral (P = 0.01).

My medical record can be used to get updated information about my health. Most (60%) interviewees said they would agree to this statement, but differences by education emerged: 59% of those with a bachelor's degree or higher said “no” or were unsure, compared with 26% of those with less education (P = 0.05).

Someone from the Biorepository can contact me to tell me about studies that involve contact with a researcher. Most (85%) interviewees said they would say “yes” to this statement. However, 67% of those who disagreed with the statement “Doctors who do medical research care only about what is best for each patient” said “no” or were unsure about medical record access, compared with 11% of those who agreed or were neutral (P = 0.05).

Unprecedented advances in biomolecular and informatics technologies are providing new ways to derive more valuable data from human biological specimens (26). Biorepositories are therefore a key resource for accelerating discovery and development of new cancer diagnostic, therapeutic, and preventive agents (1). Realizing the promise of such research, however, depends on maintaining the trust and goodwill of potential participants; thus, participants' understanding of, and reaction to, information conveyed in the informed consent process will be pivotal to the success of the research enterprise.

In this study, we obtained prospective research subjects' perspectives on an array of issues affecting participation in biorepositories within the context of detailed information provided in a consent document. Interviewees seemed to understand the information and voiced a wide range of opinions about it. Even so, majority views emerged on many issues. Considerably more than half of the interviewees were comfortable with unlimited duration of biospecimen storage; periodic contact to update their personal information and to inform them of additional research opportunities; the prospect that commercial products could be developed from the research; and that profits, if any, would not be shared among participants. More than half of the interviewees were willing to provide continuous access to their medical records, although this aspect was a primary concern for others. Interviewees generally accepted the concept of a variety of researchers having access to the Biorepository, as long as their samples and information were being put to “good use” and their confidentiality was protected. More than two thirds of participants were comfortable not receiving individual research results as a matter of routine, but many thought they should be informed of findings with serious implications for their health.

At least two overarching lessons can be drawn from these findings. First, the importance of protecting privacy and confidentiality cannot be overstated. Our survey questions intended to assess participants' level of trust in medical research seemed to indicate that the majority of this sample were either neutral or well disposed regarding the trustworthiness of medical researchers. In addition, many interviewees expressed trust in protections described in the consent form and referred to them directly in the context of other questions (generically, “it's okay as long as they don't get my name”). However, concerns about privacy were nonetheless prominent among reasons given for not participating. Furthermore, the possibility of a breach in confidentiality was foremost among likely motivations for withdrawal. Lack of trust in medical researchers also seemed to play a significant role regarding whether participants said they would refuse additional contact and continued medical record access. Protecting and promoting trust in the research enterprise is therefore essential to fostering widespread participation in biorepositories and to realizing the ultimate goals of biorepository research.

Second, biorepositories must operate in a framework of transparency and accountability. Participants are typically asked to allow their specimens and data to be used for an unlimited time and for unspecified research. Such an arrangement clearly enhances the scientific usefulness of the Biorepository, but entails risks for the participant without any countervailing direct benefits. Our findings suggest that many people are nevertheless willing to take part, and biorepositories' operating procedures should honor this altruism. Rigorous processes must be in place to ensure that samples and data are put to “good use.” Biorepositories should devise ways to communicate clearly about the research being conducted and what is being learned.

A significant strength of our study was the diversity of the study sample. Samples for previous studies have tended to be relatively homogeneous, e.g., predominantly white (11-14), predominantly or all female (12, 16), or all older adults (14).

Our study design, which constituted an in-depth “pre-test” of the consent form using surrogate subjects, was also novel. Because subjects were asked only hypothetically whether they would take part in the Biorepository, further study of actual participation rates will be needed when the consent form is put into practice. It is reasonable to expect that such rates will be lower. Pentz and colleagues (33) reported that at two health care facilities in Atlanta where cancer patients are routinely asked whether leftover tissue can be stored for research purposes, 73% of patients consented, 9% refused, and 17% took the consent form but did not return it. The opinions collected by our study, however, are useful for informing the development of biorepository policies as well as consent documents and processes.

Although our study sample was diverse, it was geographically limited, with participants drawn from the Durham, NC area only. Thus, socioeconomic and cultural factors particular to this region might have affected the nature of responses to our questions, and our findings may not be generalizable to all geographic regions.

In addition, our sample size was selected based on our primarily qualitative study design. Thus, we had limited statistical power to detect differences in the relationships among demographic characteristics, trust in medical researchers, and responses to consent statements. Future research could reveal such differences, which may prove useful for refining approaches to informed consent.

Future improvements to the consent template should focus on developing language and consent options regarding new federal policies for widespread data sharing (34) and further clarification of issues surrounding ownership of specimens and data (35, 36). In addition, research is needed on ways to enhance and simplify consent processes to maximize prospective subjects' opportunities to make an informed decision about participating in a biorepository.

Researchers are trying to learn more about cancer, heart disease, diabetes, and other health problems. Much of this research is done using human tissue or blood. Researchers often study tissue or blood from people who have health problems and from people who do not.

You are being asked to let some of your blood be stored for possible use in this kind of research. This is because you had blood drawn for medical tests ordered by your doctor. After all these tests are finished, there may be some blood left over. This leftover blood would usually be discarded because it is not needed for your care. If you agree, we would like to keep any leftover blood and some information about your health so it will be available for future research.

Your blood and information will be kept at a central place called the Duke Biorepository (just called the “Biorepository” in the rest of this consent form). Important details about the Biorepository are given below. Please read this information carefully and take your time making your decision. Be sure to ask us about anything that does not seem clear.

Some general things you should know about taking part in research are:

• Research is meant to gain knowledge that may help people in the future. You may or may not get any direct benefit from taking part. Taking part may also involve some risks.

• Research includes only those people who choose to take part. You should feel free to talk over your decision with your family, friends, doctor, and health care team.

What is the purpose of the Biorepository?

The purpose of the Biorepository is to collect and store tissue samples (such as blood) and health information for use in medical research. Researchers can do many kinds of studies using these materials. Some may use the samples and information to look for new ways to diagnose, treat, and maybe even prevent or cure health problems. Others may use them to study how genes affect health and disease, or how genes affect response to treatment (genes, which are made of DNA, give the instructions for building all the proteins that make our bodies work). Some of these studies may lead to new products, such as drugs or tests for diseases. (Insert name) is the director of the Biorepository.

What is involved if I decide to take part?

Here is what will happen:

1. We will obtain a leftover sample of your blood.

Your doctor plans to draw some of your blood for medical tests. He or she will give you the results of these tests, which will be used to plan your medical care. Even though your doctor will only take the amount of blood needed for your care, there may still be some left over after all the tests are done. This leftover blood is what we will keep.

2. We will collect some information about you and your health.

First, we will ask you for some basic information. This will include things like your name, age, and racial or ethnic group. We will also ask about your family's health history. If you agree, someone from the Biorepository will contact you no more than once a year to update this information. This will happen for as long as your sample is stored in the Biorepository.

Second, we will collect some information from your medical record. Examples include information about your diagnoses, lab results, medical procedures, and medications. This is because future researchers will need to know if you have any problems with your health. They may also need to know about any treatments you have had and how well the treatment worked. If you agree, this information will be updated from your medical record from time to time. This will also happen for as long as your sample is stored in the Biorepository.

3. We will store your blood and information.

Your blood and information will be kept at the Biorepository along with those from all the other people who decide to take part. There is no limit on the length of time we will keep your blood and information. We will keep them as long as they are useful, unless you decide you no longer want to take part or we close the Biorepository.

4. Researchers may use your blood and information in future research studies.

Researchers can apply to study the materials stored in the Biorepository. A part of your blood and some information about your health might be given to some of the researchers, along with those from many other people. However, we will not give researchers your name or any other information that could identify you without your permission. There are more details about this in the part below called “How will information about me be kept private?”

Materials stored in the Biorepository will be used mainly by Duke researchers. Researchers from other universities, the government, and drug or health-related companies can also apply to use them. Only skilled researchers will be allowed to use the samples and information. A research committee at the Biorepository must approve each study. An ethics review will also be done. This kind of review is to make sure that people who take part in research are protected.

5. Researchers may ask to do studies that involve contact with you.

You will not be notified every time your blood and information are used in a study. However, some researchers might apply to do a study for which they would need to contact you. For example, a researcher might want to do a telephone interview with people who gave their blood. If a study like this is approved, someone from the Biorepository will contact you first. We will tell you about the study so you can decide if it is okay to give the researcher your name. If you agree, the researcher will then contact you to tell you more about the study. There will be a new consent process just for that study so you can make your final decision about taking part.

We will make sure not to contact you about more than two studies like these each year. You can also decide, now or later, that you never want to be contacted about studies like these.

What are the possible risks or discomforts?

There are no physical risks to you. The main risk is that someone could get access to the data we have stored about you. If that data suggested something serious about your health, it could be misused. For example, it could be used to make it harder for you to get or keep a job or insurance. There are laws against this kind of misuse, but they may not give full protection.

We believe the chance of these things ever happening is extremely small. However, we cannot make guarantees. Your privacy and the confidentiality of your data are very important to us and we will make every effort to protect them. These efforts are described in the next section.

Blood samples will be stored in locked freezers in locked buildings. Health information and research data will be stored on secure computers that have many levels of password protection.

Your blood and health information will be labeled with a code number. Your name and anything else that could identify you will be removed and kept in a separate file. There will be a master list that links the code number to your name. This list will be stored on a secure computer with many levels of password protection. Only a few of the Biorepository staff will have access to the list and they have signed a pledge to keep your identity a secret.

Researchers who study your blood and information will not know who you are. We will only give them the code number and not any information that identifies you. The researchers must promise that they will not try to identify you. They must also promise that they will keep the coded materials secure and will not give them to anyone else.

To further protect you, we obtained a Certificate of Confidentiality from the NIH. With this Certificate, the Biorepository cannot be forced to disclose information that could identify you, even under court order, except as explained below.

The Certificate may not be used to keep information from the government that it needs to evaluate federally funded projects or information that is needed by the U.S. Food and Drug Administration. If information is disclosed to such an agency, it is no longer protected by patient privacy regulations (called ‘HIPAA’), but it will be protected by other federal privacy regulations. The Certificate does not stop you from giving information about yourself or your involvement in this project.

You will most likely not benefit directly from giving your blood for future research. The main reason you may want to take part is to help researchers make discoveries that will benefit people in the future.

There are no costs to you or your insurance. You will not be paid for taking part in the Biorepository. Your blood will be used only for research and will not be sold. You should know that research sometimes results in discoveries that may one day have commercial value. For example, discoveries could eventually lead to new tests, drugs, or other products. If this happened, you should not expect to share in any of the profits. Development of new products relies on the study of samples from hundreds or thousands of people, not on any one person.

You should not expect to get individual results from research done with your blood. Researchers must study samples from many people over many years before they can know if the results have meaning. The results will not affect your care right now. They will not be given to your doctor and will not be put in your medical record. You can get general news about studies being done through the Biorepository at (insert URL).

You can change your mind at any time about taking part in the Biorepository. Just call us at (insert phone number) and let us know. If some of your blood has already been given out for study, it cannot be taken back. Also, knowledge already gained from research using your blood cannot be destroyed. However, we will send you a form so that you can tell us in writing what you would like us to do with any of your blood that remains.

Taking part in the Biorepository is completely voluntary. If you choose to take part, you can change your mind at any time. No matter what you decide, now or in the future, it will not affect your medical care. There will not be any penalty and you will not lose any benefits you would otherwise be able to get.

You should feel free to ask any questions. Your questions should be answered clearly and to your satisfaction. For questions about the Biorepository, contact (insert name, phone number). For questions about your rights as a research volunteer, contact the Duke University Health System Institutional Review Board at (insert phone number). We will give you a signed copy of this consent form to keep.

Statement of consent.

The purpose of the Duke Biorepository, the procedures involved, and the risks and benefits have been explained to me. I have asked all the questions I have at this time and I have been told whom to contact if I have more questions. I have been told that I will be given a signed copy of this consent form to keep.

I voluntarily agree that my blood and information can be stored indefinitely at the Biorepository for use in future research to learn about, prevent, or treat health problems.

In addition, I have made the following optional choices.

No potential conflicts of interest were disclosed.

The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The authors thank Jonathan McCall for editorial assistance and manuscript preparation. We also gratefully acknowledge Drs. John M. Falletta, Geoffrey Ginsburg, Amy L. McGuire, Ross McKinney, and Debra Skinner for their input on earlier drafts of this manuscript. Timothy Flanigan, MA of RTI International, assisted in conducting the cognitive interviews.