A recent study presented to the American Public Health Association by Janice Sabin of the University of Washington in Seattle stated that the doctors subconsciously favored whites over blacks. To quote Sabin "This supports speculation that subtle race bias may affect health care, but does not imply that it will". Although the study did show a common racial bias among the general population, quoting Sabin "but we have to remember people are not racist if they hold an implicit bias."

The study involved some 400,000 people who took an online test between 2004 and 2006 about their attitudes on race. Out of which some 2,500 were doctors; 86 percent of people lived in the United States. From among the doctors 76 percent were US residents. Out of the entire group, 69 percent said they were white, while 66 percent of the doctors were white. Doctors showed a subtle preference for whites over blacks. The black doctors however did not show any preference.

Janice Sabin said, "The implicit bias effect among all test takers is very strong..... People who report they have a medical education are not different from other people, and this kind of unconscious bias is a common phenomenon".

The study suggested diversity training to be included in the curriculum of medical education in the United States. The test, which was called the 'Implicit Association Test' was developed by Anthony Greenwald, a UW psychology professor who stated "We don't call what these tests show prejudice. We talk about it as hidden bias or unconscious bias, something that most people are unaware they even possess."

The test which was created about a decade back has so far tested 6 million people that have measured unconscious attitudes about Race, gender, sexual orientation, age and various ethnic groups. Another study has shown that blacks are more likely to die from diabetes, strokes, heart attacks and cancer even though there is no difference in income, education and insurance coverage as compared to the whites.