Depictions of race and skin tone in anatomy textbooks widely used in North American medical schools could be contributing to racial bias in medical treatment, new research suggests.
Findings of the study, carried out by researchers at the University of British Columbia (UBC) and the University of Toronto (U of T), found dark skin tones are underrepresented in a number of chapters where their appearance may be the most useful, including chapters on skin cancer detection.
"We found there is little diversity in skin tone in these textbooks," said the study's lead author Patricia Louie, who began the research at UBC and is now a PhD student at U of T. "Proportional to the population, race is represented fairly accurately, but this diversity is undermined by the fact that the images mostly depict light skin tones."
For the study, researchers analyzed the race and skin tone of more than 4,000 human images in four medical textbooks: Atlas of Human Anatomy, Bates' Guide to Physical Examination & History Taking, Clinically Oriented Anatomy and Gray's Anatomy for Students.
The proportion of dark skin tones represented in all four books was very small. In Atlas, fewer than one per cent of photos featured dark skin, compared to about eight per cent in Bates', about one per cent in Clinically, and about five per cent in Gray's. More than 70 per cent of the individuals depicted in Clinically and 88 per cent in Gray's had light skin tones, while Atlas featured almost no skin tone diversity (99 per cent light skin tones).
The researchers argue that rates of mortality for some cancers-- breast, cervical, colon, lung, skin, among others-- are higher on average for black people, often due to late diagnosis.
With skin cancer, for example, physicians need to look for melanomas on nails, hands and feet, but the researchers found no visuals were provided in any of the textbooks as to what this would look like on dark-skinned patients.
UBC sociology professor and study co-author Rima Wilkes said the findings highlight a need to show greater diversity of skin tones in teaching tools used by medical schools.
"Physicians are required to recognize diseases in patients with a variety of different skin tones," said Wilkes. "When light skin-toned bodies are shown as the norm, physicians might miss signs on patients with dark skin tone because they do not know how these abnormalities will present."
The study was published in the journal Social Science & Medicine.