This information is for reference purposes only. It was current when produced and may now be outdated. Archive material is no longer maintained, and some links may not work. Persons with disabilities having difficulty accessing this information should contact us at: https://info.ahrq.gov. Let us know the nature of the problem, the Web address of what you want, and your contact information.
Please go to www.ahrq.gov for current information.
Since the enactment of the National Institutes of Health
(NIH) Revitalization Act in 1993,67 cancer researchers have put
increased emphasis on recruitment of underrepresented
populations to clinical trials. However, this aspect of the human
research enterprise has received attention primarily in the
secondary analysis of ongoing clinical trials, rather than as an
area of focused scholarship. This reality is clearly reflected in the
quality of studies available for this evidence report. One of the
positive aspects of the studies available for our review is that
they have described a number of barriers and promoters of
participation in clinical trials. However, most of the evidence is
not based on rigorous studies, and a large proportion of the
available studies were not driven by any clear hypotheses. A
major weakness of the available evidence is the limited number
of studies that compared two or more interventions, especially
randomized controlled trials. The quality of the evidence
summarized raises some questions about its adequacy to answer
our questions regarding barriers and promoters of participation
in cancer clinical trials. However, because of the consistency
and patterns of occurrence of the identified barriers and
promoters, it does provide important insights into future
Return to Contents
Recommendations and Future Research
Key Questions 1 and 2
- Much of the available body of evidence was developed as
"evidence by convenience" in the context of recruitment
difficulties, or in retrospective analyses of recruitment of
underrepresented populations across multiple clinical
trials. There is a need for well-designed, controlled studies
of strategies to improve accrual to cancer prevention and
treatment trials. These studies should be hypothesis-driven,
and include defined measures of success. They
should also meet the usual standards of the NIH peer
- Investigators should give careful thought to success
measures for recruitment of underrepresented populations,
and they should avoid setting such measures arbitrarily.
Additionally, researchers should evaluate and report
recruitment results for underrepresented groups more
- More attention should be focused on issues of trial design.
If studies are not designed to address problems that are
relevant to patients in underserved communities, then
even the best recruitment strategies will be ineffective.
Similarly, trials that exclude patients with chronic
conditions will preferentially exclude the elderly, members
of minority groups, and patients with lower
socioeconomic status, because they are more likely to have
chronic conditions. Hence, recruitment efforts must
proceed hand-in-hand with initiatives to design relevant
and pragmatic trials.68
Key Questions 3, 4, 5, and 6
- Because of many underrepresented populations' mistrust
of researchers and of research institutions, research efforts
to improve participation of underserved populations in
cancer clinical trials should be developed within the
framework of community-based participatory research,
with community involvement through all phases of the
- The need remains for community-based studies to
understand barriers to accrual in the community,
including attitudes toward clinical trial participation.
Whenever possible, such studies should be linked to the
implementation of cancer clinical trials, and include actual
recruitment as a major outcome. For example, several
studies have suggested culturally relevant education as a
strategy for improving accrual to cancer clinical trials.
There is a need to further investigate the efficacy of
culturally relevant education as a strategy to improve
accrual to cancer prevention trials and cancer treatment
- There is an urgent need to understand why participation
of the Asian American/Pacific Islander and American
Indian/Alaska Native populations in cancer clinical trials is
minimal to non-existent. Studies of barriers and promoters
of their participation should be linked to opportunities to
participate. New research initiatives in this area may
require several years before they are fruitful in terms of
trial enrollment results.
- Similarly, there is a continuing need to better understand
and improve upon strategies for recruitment of African-American males and Latinos/Hispanics into cancer clinical
trials. Ideally, such studies should include documentation
of existing barriers within a population as a basis for
tailored interventions across the spectrum of barriers and
promoters, including awareness, opportunity and
- There is a need for further investigation of effective
communication strategies, including investigations on the
best approach to deliver information about clinical trials,
both at the community level and at the point of
interaction with the potential participant.
- In communities lacking established efforts to promote
awareness about clinical trials, sufficient time should be
allowed for relationships to be built with community
members, including community-based providers, before
accrual can begin. The period for building such
relationships may take several years, but it would vary
depending on the community and the existing
relationships prior to an intervention.
- Some interventions (e.g., media-based strategy for
Hispanic women) have been shown to be effective in
increasing accrual to clinical trials. Such interventions
should be replicated, and where appropriate, the results
should be disseminated widely.
- To advance the evidence regarding efficacious strategies for
improving enrollment to cancer clinical trials, intervention
studies will need to be linked to one or more clinical trials,
depending on sample size requirements. The studies
should include collection of baseline information
regarding prevalent risk factors in the study population.
Systematic data collection about barriers and promoters of
trial participation should be linked to concrete plans for
designing interventions to address such barriers. Moreover,
the next generation of studies of barriers and promoters of
accrual should be multidisciplinary, including the
involvement of community-based participatory
researchers, social and behavioral scientists, as well as
- There are many barriers to care, and it is unlikely that
piecemeal strategies to address these barriers will be
effective to promote participation in cancer clinical trials.
There is a need for a cost-effective strategy to address
barriers to care on multiple levels, and in a manner that
can be integrated into the context of the health care
system and of the research team. To facilitate the
integration of recruitment interventions into health care
systems, especially the research team, a study should
compare the efficacy of a recruitment intervention
specialist to that of usual, opportunistic recruitment
practices. The recruitment intervention specialist would be
a professional or paraprofessional staff member who is
appropriately trained to promote awareness about clinical
trials in the community and to help patients overcome
barriers to opportunity. Ideally, the recruitment
intervention specialist would be indigenous to, or at least
have extensive familiarity with, the community targeted by
the recruitment effort. Thus, this role would be analogous
to that of a patient navigator for clinical trials, and its
cost-effectiveness should be investigated.
- Research to improve enrollment of underrepresented
populations in cancer clinical trials must interface with
other ongoing initiatives designed to address cancer health
disparities through discovery, development, and delivery.
Such efforts must overcome the critical disconnect
between discovery and development on the one hand, and
delivery of cancer care on the other.
- Substantial resources will need to be dedicated to research
efforts to build upon the existing evidence on strategies for
improving enrollment of underrepresented populations in
cancer clinical trials. Many of the initiatives that
contributed to the available evidence were probably not
funded. NCI should dedicate adequate funds for well-designed
studies of barriers and promoters of accrual to
cancer clinical trials.
Further investigation is needed on barriers to recruitment of
all of the underrepresented populations, as defined in this
report, into cancer-related clinical trials. The specific
populations are: African Americans (especially men), Hispanics,
American Indians/Alaska Natives, Asian and Pacific Islanders,
adolescents, the elderly, and rural populations. Future studies
should include the evaluation of culturally tailored strategies to
promote awareness about cancer clinical trials among
underrepresented populations. Different types of intervention
approaches should be considered to promote accrual to cancer
therapeutic trials and cancer prevention trials. Research and
evaluation of recruitment strategies may yield stronger evidence
about ways to improve participation of underrepresented
populations in cancer clinical trials. The principal need is for
hypothesis-driven research, and ultimately randomized
controlled trials, to evaluate the most promising strategies for
recruiting underrepresented populations into cancer treatment
and prevention trials.
Return to Contents
Availability of Full Report
The full evidence report from which this summary was taken
was prepared for the Agency for Healthcare Research and
Quality (AHRQ) by the Johns Hopkins University Evidence-based
Practice Center, under Contract No. 290-02-0018. Printed
copies may be obtained free of charge from the AHRQ
Publications Clearinghouse by calling 800-358-9295.
Requesters should ask for Evidence Report/Technology
Assessment No. 122, Knowledge and Access to Information on
Recruitment of Underrepresented Populations to Cancer Clinical
The Evidence Report is also online on the National Library of Medicine Bookshelf, or can be downloaded as a PDF File (1.1 MB). Plugin Software Help.
Return to Contents
1. Charlson ME, Horwitz RI. Applying results of randomized trials to clinical practice: impact of losses before randomization. BMJ 1984;289:1281-4.
2. Swanson GM, Bailar JC. Selection and description of cancer clinical trials participants—science or happenstance? Cancer 2002;9(5):950-9.
3. Sateren WB, Trimble EL, Abrams J, et al. How sociodemographics, presence of oncology specialists, and hospital cancer programs affect accrual to cancer treatment trials. J Clin Oncol 2002;20(8):2109-17.
4. Powe NR, Gary TL. Race and Research in Focus: Perspectives on Minority Participation in Health Studies: Clinical Trials Chapter. In Bettina M (Ed). 2004, American Public Health Association.
5. Berman BA, Grosser SC, Gritz ER. Recruitment to a school-based adult smoking-cessation program: do gender and race/ethnicity make a difference? J Cancer Educ 1998;13(4):220-5.
6. Brewster WR, Anton-Culver H, Ziogas A, et al. Recruitment strategies for cervical cancer prevention study. Gynecol Oncol 2002;85(2):250-4.
7. Ford M, Havstad S, Davis SD. A randomized trial of recruitment methods for older African-American Men in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Clinical Trials 2004;1:343-51.
8. Kaluzny A, Brawley O, Garson-Angert D, et al. Assuring access to state-of-the-art care for U.S. minority populations: the first 2 years of the Minority-Based Community Clinical Oncology Program. J Natl Cancer Inst 1993;85(23):1945-50.
9. Moinpour CM, Atkinson JO, Thomas SM, et al. Minority recruitment in the prostate cancer prevention trial. Ann Epidemiol 2000;10(8 Suppl):S85-91.
10. Paskett ED, Cooper MR, DeGraffinreid CR, et al. Community clinical oncology program as a recruitment vehicle for cancer control research. The Southeast Cancer Control Consortium experience. N C Med J 1995;56(6):283-6.
11. Paskett ED, Cooper MR, Stark N, et al. Clinical trial enrollment of rural patients with cancer. Cancer Pract 2002;10(1):28-35.
12. Sears SR, Stanton AL, Kwan L, et al. Recruitment and retention challenges in breast cancer survivorship research: results from a multi-site, randomized intervention trial in women with early stage breast cancer. Cancer Epidemiol Biomarkers Prev 2003;12(10):1087-90.
13. Thornquist MD, Patrick DL, Omenn GS. Participation and adherence among older men and women recruited to the Beta-Carotene and Retinol Efficacy Trial (CARET). Gerontologist 1991;31(5):593-97.
14. Zhu K, Hunter S, Bernard LJ, et al. Recruiting elderly African-American women in cancer prevention and control studies: a multifaceted approach and its effectiveness. J Natl Med Assoc 2000;92(4):169-75.
15. Advani AS, Atkeson B, Brown CL, et al. Barriers to the participation of African-American patients with cancer in clinical trials: a pilot study. Cancer 2003;97(6):1499-506.
16. Maurer LH, Davis T, Hammond S, et al. Clinical trials in a rural population: professional education aspects. J Cancer Educ 2001;16(2):89-92.
17. Linnan LA, Emmons KM, Klar N, et al. Challenges to improving the impact of worksite cancer prevention programs: comparing reach, enrollment, and attrition using active versus passive recruitment strategies. Ann Behav Med 2002;24(2):157-66.
18. Randall-David B, Stark N, Gierisch J, et al. "What do they know about it?" How the North Carolina public views cancer clinical trials: implications for primary care doctors. N C Med J 2001;62(5):281-5.
19. Alexander GA, Chu KC, Ho RC. Representation of Asian Americans in clinical cancer trials. Ann Epidemiol 2000;10(8 Suppl):S61-67.
20. Benson AB 3rd, Pregler JP, Bean JA, et al. Oncologists' reluctance to accrue patients onto clinical trials: an Illinois Cancer Center study. J Clin Oncol 1991;9(11):2067-75.
21. Goodwin JS, Hunt WC, Humble CG, et al. Cancer treatment protocols. Who gets chosen? Arch Intern Med 1988;148(10):2258-60.
22. Hunter CP, Frelick RW, Feldman AR, et al. Selection factors in clinical trials: results from the Community Clinical Oncology Program Physician's Patient Log. Cancer Treat Rep 1987;71(6):559-65.
23. Kemeny MM, Peterson BL, Kornblith AB, et al. Barriers to clinical trial participation by older women with breast cancer. J Clin Oncol 2003;21(12):2268-75.
24. Klabunde CN, Springer BC, Butler B, et al. Factors influencing enrollment in clinical trials for cancer treatment. South Med J 1999;92(12):1189-93.
25. Krailo MD, Bernstein L, Sullivan-Halley J, et al. Patterns of enrollment on cooperative group studies. An analysis of trends from the Los Angeles County Cancer Surveillance Program. Cancer 1993;71(10 Suppl):3325-30.
26. Lewis JH, Kilgore ML, Goldman DP, et al. Participation of patients 65 years of age or older in cancer clinical trials. J Clin Oncol 2003;21(7):1383-9.
27. Murthy VH, Krumholz HM, Gross CP. Participation in cancer clinical trials: race-, sex-, and age-based disparities. JAMA 2004;291(22):2720-6.
28. Schiffman M , Adrianza ME. ASCUS-LSIL Triage Study. Design, methods and characteristics of trial participants. Acta Cytol 2000;44(5):726-42.
29. Simon MS, Du W, Flaherty L, et al. Factors associated with breast cancer clinical trials participation and enrollment at a large academic medical center. J Clin Oncol 2004;22(11):2046-52.
30. Trimble EL, Carter CL, Cain D. Representation of Older Patients in Cancer Treatment Trials. Cancer 1994;74(7):2208-14.
31. Yee KW, Pater JL, Pho L, et al. Enrollment of older patients in cancer treatment trials in Canada: why is age a barrier? J Clin Oncol 2003;21(8):1618-23.
32. Zhu K, Hunter S, Bernard LJ, et al. Recruiting elderly African-American women in cancer prevention and control studies: a multifaceted approach and its effectiveness. J Natl Med Assoc 2000;92(4):169-75.
33. Adams-Campbell LL, Ahaghotu C, Gaskins M, et al. Enrollment of African Americans onto clinical treatment trials: study design barriers. J Clin Oncol 2004;22(4):730-4.
34. Sears SR, Stanton AL, Kwan L, et al. Recruitment and retention challenges in breast cancer survivorship research: results from a multisite, randomized intervention trial in women with early stage breast cancer. Cancer Epidemiol Biomarkers Prev 2003;12(10):1087-90.
35. Broome ME, Richards DJ. The influence of relationships on children's and adolescents' participation in research. Nurs Res 2003;52(3):191-7.
36. Advani AS, Atkeson B, Brown CL, et al. Barriers to the participation of African-American patients with cancer in clinical trials: a pilot study. Cancer 2003;97(6):1499-506.
37. Bieniasz ME, Underwood D, Bailey J, et al. Women's feedback on a chemopreventive trial for cervical dysplasia. Appl Nurs Res 2003;16(1):22-8.
38. Comis RL, Miller JD, Aldige CR, et al. Public attitudes toward participation in cancer clinical trials. J Clin Oncol 2003;21(5):830-5.
39. Brown DR, Topcu M. Willingness to participate in clinical treatment research among older African Americans and whites. Gerontologist 2003;43(1):62-72.
40. Grunfeld E, Zitzelsberger L, Coristine M, et al. Barriers and facilitators to enrollment in cancer clinical trials: qualitative study of the perspectives of clinical research associates. Cancer 2002;95(7):1577-83.
41. Kornblith AB, Kemeny M, Peterson BL, et al. Survey of oncologists' perceptions of barriers to accrual of older patients with breast carcinoma to clinical trials. Cancer 2002;95(5):989-96.
42. Diener-West M, Hawkins BS, Moy CS, et al., for the Collaborative Ocular Melanoma Study Group. Sociodemographic and clinical predictors of participation in two randomized trials: findings from the Collaborative Ocular Melanoma Study COMS report no. 7. Control Clin Trials 2001;22(5):526-37.
43. Randall-David B, Stark N, Gierisch J, et al. "What do they know about it?" How the North Carolina public views cancer clinical trials: implications for primary care doctors. N C Med J 2001;62(5):281-5.
44. Pinto HA, McCaskill-Stevens W, Wolfe P, et al. Physician perspectives on increasing minorities in cancer clinical trials: an Eastern Cooperative Oncology Group (ECOG) Initiative. Ann Epidemiol 2000;10(8 Suppl):S78-84.
45. Fouad MN, Partridge E, Green BL, et al. Minority recruitment in clinical trials: a conference at Tuskegee, researchers and the community. Ann Epidemiol 2000;10(8 Suppl):S35-40.
46. Brown DR, Fouad MN, Basen-Engquist K, et al. Recruitment and retention of minority women in cancer screening, prevention, and treatment trials. Ann Epidemiol 2000;10(8 Suppl):S13-21.
47. Fouad MN, Partridge E, Wynn T, et al. Statewide Tuskegee Alliance for clinical trials. A community coalition to enhance minority participation in medical research. Cancer 2001;91(1 Suppl):237-41.
48. Outlaw FH, Bourjolly JN, Barg FK. A study on recruitment of black Americans into clinical trials through a cultural competence lens. Cancer Nurs 2000;23(6):444-51, quiz 451-2.
49. Chen CI, Skingley P, Meyer RM. A comparison of elderly patients with aggressive histology lymphoma who were entered or not entered on to a randomized phase II trial. Leuk Lymphoma 2000;38(3-4):327-34.
50. Ling J, Rees E, and Hardy J. What influences participation in clinical trials in palliative care in a cancer centre? Eur J Cancer 2000;36(5):621-6.
51. Lee MM, Chamberlain RM, Catchatourian R, et al. Social factors affecting interest in participating in a prostate cancer chemoprevention trial. J Cancer Educ 1999;14(2):88-92.
52. McCaskill-Stevens W, Pinto H, Marcus AC, et al. Recruiting minority cancer patients into cancer clinical trials: a pilot project involving the Eastern Cooperative Oncology Group and the National Medical Association. J Clin Oncol 1999;17(3):1029-39.
53. Twelves CJ, Thomson CS, Young J, et al. Entry into clinical trials in breast cancer: the importance of specialist teams. Scottish Breast Cancer Focus Group and Scottish Cancer Therapy Network. Eur J Cancer 1998;34(7):1004-7.
54. Mouton CP, Harris S, Rovi S, et al. Barriers to black women's participation in cancer clinical trials. J Natl Med Assoc 1997;89(11):721-7.
55. Roberson NL. Clinical trial participation. Viewpoints from racial/ethnic groups. Cancer 1994;74(9 Suppl):2687-91.
56. Lerman C, Rimer BK, Daly M, et al. Recruiting high risk women into a breast cancer health promotion trial. Cancer Epidemiol Biomarkers Prev 1994;3(3):271-6.
57. Millon-Underwood S, Sanders E, Davis M. Determinants of participation in state-of-the-art cancer prevention, early detection/screening, and treatment trials among African-Americans. Cancer Nurs 1993;16(1):25-33.
58. Kemp N, Skinner E, Toms J. Randomized clinical trials of cancer treatment—a public opinion survey. Clin Oncol 1984;10(2):155-61.
59. Spaight SJ, Nash S, Finison LJ, et al. Medical oncologists' participation in cancer clinical trials. Prog Clin Biol Res 1984;156:49-61.
60. Woods MN, Harris KJ, Mayo MS, et al. Participation of African Americans in a smoking cessation trial: A quantitative and qualitative study. J Natl Med Assoc 2002;94(7):609-18.
61. Green BL, Partridge EE, Fouad MN, et al. African-American attitudes regarding cancer clinical trials and research studies: results from focus group methodology. Ethn Dis 2000;10(1):76-86.
62. Robinson SB, Ashley M, and Haynes MA. Attitude of African-Americans regarding prostate cancer clinical trials. J Community Health 1996;21(2):77-87.
63. Moore DH. Ovarian cancer in the elderly patient. Oncology 1994;8:21-25.
64. Richardson JL, Myrtle R, Solis JM, et al. Participation of community medical oncologists in clinical research trials. Prog Clin Biol Res 1986;216:269-80.
65. Pinto BM, Clark MM, Maruyama NC, et al. Psychological and fitness changes associated with exercise participation among women with breast cancer. Psychooncology 2003;12(2):118-26.
66. Fallowfield L, Ratcliffe D, Souhami R. Clinicians' attitudes to clinical trials of cancer therapy. Eur J Cancer 1997;33(13):2221-9.
67. National Institutes of Health. 1993. NIH guidelines on the inclusion of women and minorities as subjects in clinical research. Available at: http://grants.nih.gov/grants/funding/women_min/guidelines_update.htm. Accessed October 1, 2004.
68. Corrie P, Shaw J, Harris R. Rate limiting factors in recruitment of patients to clinical trials in cancer research: descriptive study. BMJ 2003;327(7410):320-1.
Return to Contents
AHRQ Publication Number 05-E019-1
Current as of June 2005