Do doctors discriminate by race?

Two 50-year-old men arrive at an emergency room with acute chest pain. One is white and the other black. Will they receive the same quality of treatment and have the same chance of recovery? Many experts today insist that bias in the doctor's office will lead to poorer treatment of the minority patient. This notion has taken hold in medical schools, health organizations (the American Public Health Association issued a call for "Research and Intervention on Racism as a Fundamental Cause of Ethnic Disparities in Health"), and in Congress, where Democrats proposed a health bill "to end discrimination ... and expand the Office of Civil Rights."

To be sure, minorities as a group have poorer health status. Compared to whites, infant mortality rates are higher, life expectancy is lower, and the prevalence of diabetes, asthma, and obesity, for example, are higher. But there is little compelling evidence supporting the idea that racially biased doctors are a cause of poor minority health.

The notion of physician bias was popularized in 2002 by a report from the Institute of Medicine (IOM) called "Unequal Treatment: Confronting Racial and Ethnic Disparities in Health Care." It found that, on average, white patients get certain procedures (e.g., catheterization) more often than black patients, and concluded that "bias," "prejudice," and "discrimination" within the doctor/patient relationship was a major, though not exclusive, cause.

But the conclusions were not supported by data. In fact, the IOM authors put far too much weight on studies in which important data were missing. The most rigorous studies reviewed by the IOM sought to control for confounding clinical or economic variables, such as concurrent illness, supplemental insurance, or patients' refusal to undergo procedures. But because most of the studies were retrospective and relied upon chart review or large Medicare administrative databases, many such variables could not be captured.

Details that figure importantly in physician decision making--like EKG subtleties, position of occlusion in carotid and coronary vessels, coronary ejection fraction, and pulmonary function test performance--will not show up in most after-the-fact reviews. Moreover--and this is critical--these unrecorded variables do vary by race and ethnicity.

Racial bias need not be at work. More compelling explanations for the treatment gap exist. Two factors in particular have far more potent influence on the quality of care an individual receives, irrespective of race: the doctor pool available to the patient, and where the patient lives.

Peter Bach of Memorial Sloan Kettering Cancer Center and his colleagues showed that white and black patients, on average, do not visit the same population of physicians. Moreover, the doctors frequented by black patients were often not in a position to provide optimal care. Bach's study, which appeared in the New England Journal of Medicine in 2004, found that physicians who treated a large number of black patients were more likely to answer "not always" when asked whether they had access to high-quality specialists (such as cardiologists or gastroenterologists) or services like diagnostic imaging or home health assistance.