Case Comprehensive Cancer Center Cultural Competency Series
September 23, 2015
Unconscious Bias: Cancer Clinical Trial Disparities in Racial and Ethnic Minority
Populations
Prepared by Aaron McCorkle, BA – Cleveland Clinic Foundation
Unconscious Bias and Health Disparities
Implicit social cognition, or unconscious bias, allows individuals to use portions of prior
experiences to affect performance, although it may not be introspectively realized (Greenwald &
Banaji, 1995). The Center for Disease Control and Prevention (2008) define health disparities as
“preventable differences in the burden of disease, injury, violence or opportunities to achieve
optimal health that are experienced by socially disadvantaged populations.” Some researchers
suggest that unconscious bias is a more likely underlying cause of treatment disparities than
overt prejudice (Green et al., 2007). Because of this, the juxtaposition of unconscious bias and
health disparities seems logical, if not necessary, when considering the lack of minority
involvement in cancer clinical trial research. This review will take a preliminary look at the
relationship between unconscious bias and health disparities and how it impacts cancer clinical
trial research for racial minority populations.
Does unconscious bias exist in clinical trials research?
Researchers at the University of California (UC), Davis (2014) estimate that less than five
percent of clinical trial participants are minorities, which comes 20 years after Congress
mandated the inclusion of minorities in research funded by the National Institutes of Health.
Dr. Moon Chen, who led minority research efforts at UC Davis, believes that an emphasis on
minority-centered research and greater recruitment efforts will help increase minority accrual to
cancer clinical trials. Unconscious bias is a socio-behavioral phenomenon, and as such, can occur
in individuals throughout society. Unconscious bias may also affect the communication and
health care provided to individuals within minority groups (Blair, Steiner, & Havranek, 2011),
while some data also suggests that health care providers harbor prejudice (bias/stereotyping)
toward minority groups (King, 2002). Dr. Michelle van Ryn, director of Mayo Clinic’s Research
Program on Equity and Inclusion in Health Care, believes that unconscious biases and processes
affect health care providers. Dr. Ryn contends that in situations of stress and fatigue, health care
providers may unconsciously rely upon preexisting cognitive information and stereotypes
(personal communication, April 2, 2015). Minority patients can reciprocate with feelings of
mistrust and hesitance when complying to treatment and this may adversely impact minority
participation in clinical trials, beginning with the informed-consent process (King, 2002).
Can unconscious bias affect the receipt of cancer treatment and outcomes for minority
patients?
Because unconscious bias is present among clinicians, it can be inferred that health care
disparities among minorities are, in part, a derivative of this behavior (Blair et al., 2011).
Disparities in minority clinical trial participation highlight the insufficiency of clinical research
to determine treatment efficacy for these racial groups (Doamekpor & Zuckerman, 2014).
According to Doamekpor and Zuckerman (2014), “naturally occurring genetic variations may
influence the way certain drugs are metabolized and work in members of specific racial and
ethnic groups […],” which underscores the need for equal cancer treatment for minorities. In a
study of the underuse of adjuvant breast cancer in minorities, Bickell et al. (2006) found racial
disparities in multiple types of therapies. The lack of “efficacious adjuvant therapy in a woman
with newly diagnosed early-stage breast cancer was 21% overall; 16% among whites, 23%
among Hispanics, and 34% among black women (Bickell et al., 2006).” Shavers and Brown
(2002) noted a continual trend of racial disparity when considering receipt of treatment for
multiple therapy types, including primary and adjuvant therapy. Shavers and Brown (2002) also
concur that “studies of clinical trials and equal-access systems support the idea that equal
treatment will yield similar cancer outcomes between racial/ethnic minorities and whites with
similar disease.” Additionally, the reduction of nonclinical factors, which include unconscious
bias, may provide greater opportunities for minorities in need of receiving cancer treatment on
clinical trials (Shavers & Brown, 2002).
How can we reduce treatment disparities influenced by unconscious bias in clinical trials?
Unconscious bias is something that cannot be ignored when considering the delivery of clinical
care. If healthcare is to be egalitarian and reduce bias, education and awareness initiatives must
be implemented for healthcare providers (Dr. M. Ryn, personal communication, April, 2015).
Reducing impediments to minority healthcare access and increasing minority recruitment to
clinical trials must also be considered. Researchers must also be mindful that these impediments
can intangible variables like fatalistic attitudes, misperceptions and mistrust in the healthcare
system, as well as fears of experimentation (Bruner, Jones, Buchanan, & Russo, 2006). Clinical
trials literature advocates that “racial/ethnic minority and white patients who receive similar care
for the same stage of disease have shown to have similar survival experiences for multiple
myeloma and cancers of the cervix, lung, colon and prostate (Shavers & Brown, 2002).” As
clinical trials research continues to develop, healthcare institutions should also consider
establishing interventions to reduce disparities in clinical care and combat issues that persist with
unconscious bias.
References and Resources
Benz, J., Espinosa, O., Welsh, V., Fontes, A. (2011). Awareness Of Racial And Ethnic Health
Disparities Has Improved Only Modestly Over A Decade. Health Affairs, 30(10), 18601867. doi: 10.1377/hlthaff.2010.0702
Bickell, N. (2006). Missed Opportunities: Racial disparities in adjuvant breast cancer treatment.
Journal of Clinical Oncology, 24(9), 1357-1362.
Blair, I., Steiner, J., Fairclough, D., Hanratty, R., Price, D., Hirsh, H., . . . Havranek, E. (2013).
Clinicians' implicit ethnic/racial bias and perceptions of care among black and latino
patients. The Annals of Family Medicine, 11(1). 43-52.
Blair, I., Steiner, J., Havranek, E. (2011). Unconscious (implicit) bias and health disparities:
where do we go from here? The Permanente Journal, 15(2), 71-78.
Bruner, D., Jones, M., Buchanan, D., Russo, J. (2006). Reducing cancer disparities for
minorities: a multidisciplinary research agenda to improve patient access to health
systems, clinical trials, and effective cancer therapy. Journal of Clinical Oncology,
24(14) 2209-2215.
Doamekpor, L., & Zuckerman, D. (2014). Lack of diversity in cancer drug clinical trials may
exacerbate racial disparities in mortality rates. Cancer Epidemiology, 38, 645-646.
Green, A., Carney, D., Pallin, D., Ngo, L., Raymond, K., Iezzoni, L., & Banaji, M. (2007).
Implicit bias among physicians and its prediction of thrombolysis decisions for black and
white patients. Journal of General Internal Medicine, 22, 1231-1238.
Greenwald, A., & Banaji, M. (1995). Implicit social cognition: attitudes, self-esteem, and
stereotypes. Psychological Review, 102 (1), 4-27.
King, T. (2002). Racial disparities in clinical trials. New England Journal of Medicine N Engl J
Med, 346(18) 1400-1402.
Ryn, M. (Interviewee). (2015). Targeting Unconscious Bias in Health Care [Interview
transcript]. Retrieved from Mayo Clinic News Network Web site:
http://newsnetwork.mayoclinic.org/discussion/targeting-unconscious-bias-in-health-care/
Shavers, V., & Brown, M. (2002). Racial and ethnic disparities in the receipt of cancer treatment.
Cancer Spectrum Knowledge Environment 94(5), 334-357.
Stanford Medicine News Center. (2015, January 26). Evidence-based care eliminates racial
disparity in colon cancer survival rates, study finds: A new study finds that equitable
delivery of evidence-based care eliminates the racial disparity in colon-cancer survival
rates. Retrieved from https://med.stanford.edu/news/all-news/2015/01/evidence-basedcare-eliminates-racial-disparity-in-colon-cancer.html
UC Davis Health System. (2014, March 18). Minority clinical trials participation and analysis
still lag 20 years after federal mandate: UC Davis researchers urge renewed recruitment
and research effort. Retrieved from
http://www.ucdmc.ucdavis.edu/publish/news/newsroom/8305