Subconscious automatic associations on race and social class did not show through in the doctors' clinical decisions.
Using social psychology tests of attitudes and associations, the researchers assessed unconscious preferences for black versus white individuals, and upper-class versus lower-class individuals, for the study published in JAMA Surgery.
The "implicit association tests" for race and class measured the strength of automatic associations, and the results showed most of the 215 clinician respondents - surgeons, fellows, residents, interns and physicians - had bias.
The following biases were found in the scores of unconscious attitudes:
- Moderate preferences in the race implicit association test (IAT)
- Strong preferences in the social class IAT.
But the same survey respondents, when tested on their clinical decisions, showed no influence on patient management introduced by their equality biases, in the analysis by Dr. Adil Haider, of Brigham and Women's Hospital in Boston, MA, and co-authors.
The authors conclude:
"Although this study of clinicians from surgical and other related specialties did not demonstrate any association between implicit race or social class bias and clinical decision making, existing biases might influence the quality of care received by minority patients and those of lower socioeconomic status in real-life clinical encounters."
Bias was suggested in certain clinical scenarios
While the researchers found no differences overall in patient treatment according to race or social class, certain clinical scenarios did suggest a bias.
For instance, clinicians were more likely to diagnose a young black woman with pelvic inflammatory disease rather than appendicitis when compared with a young white woman with the same symptoms and history.
Another difference, although also not significant in further analysis, was that an MRI scan was less likely to be ordered for neck tenderness after a motor vehicle accident if the patients were of low rather than high socioeconomic status.
The authors call for research that looks into real patient outcomes from actual clinical interactions "to clarify the effect of clinician implicit bias" on provision of care.
The web-based survey used to test the clinicians at the Johns Hopkins Hospital, Baltimore, MD, is online via traumastudy.com.
The respondents had been led to think the survey was part of a quality improvement and patient safety study, so that response bias was reduced compared with knowing the study was specifically about the clinicians' unconscious prejudices.
Unconscious attitudes were assessed from the strength of automatic associations, which were tested according to the speed of response on computer keys - on the basis that it is easier to make quick associations that match implicit attitudes.
The study included four race and four social class vignettes. Detailed information about IAT testing, as used in this research, is available at Project Implicit - set up by an international collaboration of researchers to create a virtual laboratory investigating "thoughts and feelings outside of conscious awareness and control."