APPENDIX A: Attitudes and Intention to Enroll in therapeutic clinical Trials (AIET) 1. Trust in the doctor who offers you the trial 1=Not at all 5=Very much 2. The reputation of the treatment center where the trial is done 1=Not at all 5=Very much 3. I can not trust health care workers 1=Str. Disagree 5=Str.Agree 4. I am suspicious of clinical trials 1=Str. Disagree 5=Str.Agree 5. I am suspicious of information I receive from researchers 1=Str. Disagree 5=Str.Agree 6. Most clinical research is ethical 1=Str.Agree 5=Str. Disagree 7. Researchers do not care about me or my well being 1=Str. Disagree 5=Str.Agree

8. My doctor would not ask me to participate in a clinical trial if he or she thought it would hurt me 1=Str.Agree 5=Str. Disagree

9. I am confident the group of people who approve clinical trials make sure all participants are treated fairly 1=Str.Agree 5=Str. Disagree

10. How likely do you think it is that you might be used as a guinea pig if you were in a clinical trial? 1=Not at all likely 5=Very likely 11. I could still ask my doctors any questions that I want to 1=Str.Agree 5=Str. Disagree 12. If doctors took my blood they could do tests on it they have not told me about 1=Str. Disagree 5=Str.Agree 13. I would only be agreeing to do what is explained to me in the consent form 1=Str.Agree 5=Str. Disagree 14. I could still change my mind about participating at any time 1=Str.Agree 5=Str. Disagree 15. The researchers would only do what is stated in the consent form 1=Str.Agree 5=Str. Disagree 16. Black people in clinical trials receive the same care from doctors and health care workers as people of other races or ethnicities on clinical trials 1=Str.Agree 5=Str. Disagree 17. If I were to enroll in a clinical trial my doctors would treat me with dignity and respect 1=Str.Agree 5=Str. Disagree 18. Compared with others, poor people are used more in research without their permission 1=Str. Disagree 5=Str.Agree 19. How often, if ever, do you think doctors prescribe medication as a way of experimenting on Black patients without their knowledge or permission? 1=Never 5=Very often

20. Black people are used more in research without their knowledge or permission than others races and ethnicities 1=Str. Disagree 5=Str.Agree 21. People can access my medical records without my approval. 1=Str. Disagree 5=Str.Agree 22. My medical records are kept private. 1=Str.Agree 5=Str. Disagree 23. My privacy is a major concern for the researchers involved 1=Str.Agree 5=Str. Disagree 24. Personal information like my name, address and phone number will remain confidential 1=Str.Agree 5=Str. Disagree 25. Any center doing clinical trials has set rules to make sure my records are kept safe 1=Str.Agree 5=Str. Disagree 26. There are always serious side effects related to clinical trials 1=Str. Disagree 5=Str.Agree

27. If my doctor wanted me to participate in a clinical trial, he or she would fully explain to me everything that is involved 1=Str.Agree 5=Str. Disagree 28. I can talk to my doctors to find out about participating in clinical trials 1=Str.Agree 5=Str. Disagree 29. There may be benefits for me if I participate in a clinical trial 1=Str.Agree 5=Str. Disagree 30. There may be benefits for other people like me if I participate in a clinical trial 1=Str.Agree 5=Str. Disagree

31a. At this moment, is it likely that you would sign up to participate in a therapeutic clinical trial

31b. (Same Question) At this moment, is it likely that you would sign up to participate in a therapeutic clinical trial APPENDIX B: Item Analysis Fear and distrust of the medical establishment (doctors, scientists and the government)

Strongly Somewhat Neither Somewhat Strongly p-value Agree Agree Disagree Disagree I can not trust health care workers Pre 5 19 4 27 45 Post 2 10 4 20 64 Change -3 -9 0 -7 19 0.006 I am suspicious of clinical trials Pre 13 37 12 18 20 Post 3 21 4 32 40 Change -10 -16 -8 14 20 <0.001 I am suspicious of information I receive from researchers Pre 12 31 11 27 19 Post 2 22 4 31 42 Change -10 -9 -7 4 23 <0.001

Concern about the ethical conduct of investigators Researchers do not care about me or my well being Pre 10 19 10 32 29 Post 5 8 9 23 55 Change -5 -11 -1 -9 26 <0.001 My doctor would not ask me to participate in a clinical trial if he or she thought it would hurt me Pre 60 23 3 8 6 Post 82 14 4 0 0 Change 22 -9 1 -8 -6 <0.001 Black people in clinical trials receive the same care from doctors and health care workers as people of other races or ethnicities on clinical trials Pre 15 34 11 20 20 Post 46 23 9 17 5 Change 31 -11 -2 -3 -15 <0.001 Worry that investigators will treat poor or minority patients unfairly If I were to enroll in a clinical trial my doctors would treat me with dignity and respect Pre 50 35 8 7 0 Post 84 12 3 1 0 Change 34 -23 -5 -6 0 <0.001

Compared with others, poor people are used more in research without their permission Pre 28 21 23 16 12 Post 11 19 14 24 32 Change -17 -2 -9 8 20 <0.001 I believe that Black people are used more in research without their knowledge or permission than others races and ethnicities Pre 23 25 22 14 16 Post 8 19 16 18 39 Change -15 -6 -6 4 23 <0.001 Loss of Privacy I believe that if I enroll in a clinical trial people can access my medical records without my approval. Pre 25 19 8 18 30 Post 12 18 5 21 44 Change -13 -1 -3 3 14 0.002 Personal information like my name, address and phone number will remain confidential Pre 53 31 7 3 7 Post 66 24 5 4 2 Change 13 -7 -2 1 -5 0.03 Any center doing clinical trials has set rules to make sure my records are kept safe Pre 55 34 6 2 4 Post 80 14 5 1 0 Change 25 -20 -1 -1 -4 <0.001 The lack of knowledge and awareness of clinical trials There are always serious side effects related to clinical trials Pre 22 19 17 30 12 Post 12 24 11 25 28 Change -10 5 -6 -5 16 <0.001 I can talk to my doctors to find out about participating in clinical trials Pre 64 32 2 2 0 Post 88 9 2 1 0 Change 24 -23 0 -1 0 <0.001 There may be benefits for other people like me if I participate in a clinical trial Pre 68 28 2 2 1 Post 82 12 5 1 0 Change 14 -16 3 -1 -1 0.02 At this moment, is it likely that you would sign up to participate in a therapeutic clinical trial Pre 15 33 17 14 21 Post 51 25 15 6 4 Change 36 -8 -2 -8 -17 <0.001 Fear of losing one’s rights by signing a research informed consent document If doctors took my blood they could do tests on it they have not told me about

Pre 32 32 8 12 16 Post 15 32 6 16 31 Change -17 0 -2 4 15 <0.001 I would only be agreeing to do what is explained to me in the consent form

Pre 61 29 6 1 4 Post 81 15 2 2 1 Change 20 -14 -4 1 -3 0.001 I could still change my mind about participating at any time Pre 75 21 1 2 1 Post 94 5 1 0 0 Change 19 -16 0 -2 -1 <0.001