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, Davis (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 (Dayer & Crane, 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 (Dayer & Crane, 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.