Rarely has a study received as much attention, and generated as much controversy, as the February 25, 1999 New England Journal of Medicine article, “The Effect of Race and Sex on Physicians' Recommendations for Cardiac Catheterization.” The suggestion that subconscious bias might play a role in explaining racial and ethnic disparities in care drew criticism about its statistical methods, reporting of results, and interpretation of findings. It attracted widespread attention from the nation's major newspapers, television newscasts, and ABC's Nightline.

The LDI study team, led by alum Kevin Schulman, included Jesse Berlin, Sankey Williams, John Eisenberg, and Jose Escarce. They asked 720 primary care doctors to watch videotapes in which patient-actors—two black men, two black women, two white men, and two white women—described their chest pain. The actors wore identical gowns, reported the same clinical symptoms, and had the same insurance coverage and profession. Having standardized these factors, the researchers found that blacks had a 7% lower probability of being referred for cardiac catheterization, primarily driven by fewer referrals for black women.

It put the issue of health disparities squarely on the public agenda, and soon thereafter Congress  funded the landmark Institute Of Medicine (IOM) report, Unequal Treatment: Confronting Racial and Ethnic Disparities in Health Care.” The report discussed the Schulman controversy, stating,

“The real implication of the study was actually quite simple: doctors are human. Like lawyers, businesspeople, and other professionals, doctors are fallible and may discriminate, either consciously or subconsciously…this study simply concluded that racial bias can affect who gets into the operating room.”