By Shankar Vedantam
Monday, August 13, 2007; A03
Long before word recently broke that white referees in the National Basketball Association were calling fouls at a higher rate on black athletes than on white athletes, and long before studies found racial disparities in how black and white applicants get called for job interviews, researchers noted differences in the most troubling domain of all — disparities in survival and health among people belonging to different racial groups.
Black babies, according to the federal government’s Centers for Disease Control and Prevention, have higher death rates than white babies. Black women are more than twice as likely as white women to die of cervical cancer. And in 2000, the death rate from heart disease was 29 percent higher among African Americans than among white adults, and the death rate from stroke was 40 percent higher.
The trouble with all these numbers, as with the NBA study — which was conducted by researchers Justin Wolfers and Joseph Price — is that they do not explain why such differences exist among racial groups.
Some studies have shown, similar to the NBA analysis, that diagnoses and treatments offered by physicians vary between racial groups, for diseases as dissimilar as heart disease and schizophrenia. But does this reflect physician bias, or the possibility that patients from different backgrounds present themselves differently? Could race be a marker for some other variable that really matters, such as health insurance status?
A new study by researchers at Massachusetts General Hospital and other institutions affiliated with Harvard University provides empirical evidence for the first time that when it comes to heart disease, bias is the central problem — bias so deeply internalized that people are sincerely unaware that they hold it. (Story below.)
Physicians who were more racially biased were less likely to prescribe aggressive heart-attack treatment for black patients than for whites. The study was recently published in the Journal of General Internal Medicine.
The research finding cannot be automatically extrapolated to the NBA or other domains, but it does suggest a mechanism by which disparities emerge. No conscious bias was apparently present — there was no connection between the explicit racial views of physicians and disparities in their diagnoses. It was only when researchers studied physicians’ implicit attitudes — by measuring how quickly they made positive or negative mental associations with blacks and whites — that they found a mechanism to explain differences in medical judgment.
“Physicians who had higher biases against blacks were less likely to recommend thrombolysis for blacks,” said Alexander R. Green, the study’s chief investigator and a faculty member at the Disparities Solutions Center at Massachusetts General Hospital.
Thrombolysis is a clot-busting technique given when doctors suspect that a patient is having a heart attack. It is not to be given lightly, which is why a physician’s judgment is crucial in telling patients who are merely having aches and pains apart from patients at death’s door.
Green had 287 physicians at four academic medical centers in Boston and Atlanta take a psychological test for bias. He followed it up by providing a case study of a 50-year-old man called “Mr. Thompson,” a smoker with a history of hypertension, “who presents to the emergency department with chest pain. He appears to be in a lot of pain describing it as ‘sharp, like being stabbed with a knife.’ “
The patient was described to some physicians as white and to others as black. Physicians were asked to decide whether the pain was the result of coronary artery disease and whether to prescribe clot-busting drugs.
Doctors were more likely to think “Mr. Thompson” was having a heart attack when he was black than when he was white. But they did not prescribe treatment to reflect this — physicians who thought a black Mr. Thompson was having a heart attack prescribed thrombolysis less often than when they thought a white Mr. Thompson was having one.
Green said numerous other studies are underway to evaluate the utility of psychological tests for bias to explain disparities in medical domains. “We have reason to suspect you can measure unconscious bias among physicians and show it has an impact on treatment decisions,” he said.
Mahzarin Banaji, a co-author and Harvard psychologist who helped develop the Implicit Association Test used in this study, said the racial bias unearthed by the study is at odds with conventional views of bigotry — and perhaps more insidious. Rather than harboring deliberate ill will, she said, the physicians had apparently internalized racial stereotypes, and these attitudes subtly influenced their medical judgment without their even realizing it.
The study of physicians had one hopeful note, Banaji said: Doctors at least were willing to open their subconscious minds for inspection, which is something that many other professionals — judges, police officers and NBA referees — rarely are willing to do.
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Study seeks root of known disparity
By Stephen Smith, Boston Globe | July 20, 2007
Deeply imbedded attitudes about race influence the way doctors care for their African- American patients, according to a Harvard study that for the first time details how unconscious bias contributes to inferior care.
Researchers have known for years that African-Americans in the midst of a heart attack are far less likely than white patients to receive potentially life-saving treatments such as clot-busting drugs, a dramatic illustration of America’s persistent healthcare disparities. But the reasons behind such stark gaps in care for heart disease, as well as cancer and other serious illnesses, have remained murky, with blame fixed on doctors, hospitals, and insurance plans.
In the new study, trainee doctors in Boston and Atlanta took a 20-minute computer survey designed to detect overt and implicit prejudice. They were also presented with the hypothetical case of a 50-year-old man stricken with sharp chest pain; in some scenarios the man was white, while in others he was black.
“We found that as doctors’ unconscious biases against blacks increased, their likelihood of giving [clot-busting] treatment decreased,” said the lead author of the study, Dr. Alexander R. Green of Massachusetts General Hospital. “It’s not a matter of you being a racist. It’s really a matter of the way your brain processes information is influenced by things you’ve seen, things you’ve experienced, the way media has presented things.”
Specialists predict that the novel study, appearing on the website of the Journal of General Internal Medicine, will result in considerable soul-searching in the medical profession, rethinking of medical school curriculum, and refresher courses for veteran doctors.
“Years of advanced education and egalitarian intentions are no protection against the effect of implicit attitudes,” said Dr. Thomas Inui, president of the Regenstrief Institute Inc. in Indianapolis, which studies vulnerable patient groups. “When do they surface? When we’re involved with high-pressure, high-stakes decision-making, when there’s a lot riding on our decisions but there isn’t a lot of time to make them, that’s when the implicit attitudes that are not scientific rise up and grab us.”
Green said he cannot explain why implicit bias would cause doctors to deprive patients of potentially life-saving therapy, and other researchers said they do not know how big a factor unconscious prejudice is in the far-reaching problem of disparities.
The best way to combat those impulses is by acknowledging them, specialists said, suggesting that medical personnel take a test to measure unconscious bias, such as one at implicit.harvard.edu.
“The great advantage of being human, of having the privilege of awareness, of being able to recognize the stuff that is hidden, is that we can beat the bias,” said Mahzarin R. Banaji, a Harvard psychologist who helped design a widely used bias test.
Dr. JudyAnn Bigby, Massachusetts secretary of health and human services and a specialist in healthcare disparities, said the study demonstrates the importance of monitoring how hospitals and large physician practices provide care to patients of different races.
But Inui and other specialists said that even conquering doctor bias will not be enough to eliminate healthcare disparities.
A succession of studies during the past decade has demonstrated graphically the scope of disparities and the complexity of the problem, which touches on issues from poverty to geography to genetics.
Black patients in the process of having a heart attack, for example, are only half as likely as whites to get clot-busting medication, and they are much less likely to undergo open-heart surgery. Similarly, African-American women receive breast-cancer screenings at a rate substantially lower than white women. Fewer black babies live to celebrate their first birthdays: In Massachusetts, the mortality rate for black infants is more than double the rate for white babies.
Healthcare disparities emerged as a national issue with the 2002 release of a landmark study titled “Unequal Treatment” that was commissioned by Congress and produced by the Institute of Medicine. In Boston, the city health department released a sweeping blueprint for addressing disparities two years ago, with Mayor Thomas M. Menino describing the issue as the most pressing health problem confronting the city.
“Most physicians are now willing to acknowledge that important disparities exist in the healthcare system,” said Dr. John Ayanian, a healthcare policy specialist at Brigham and Women’s Hospital who was not involved with the new research. “There’s still a barrier, though, to many physicians acknowledging that disparities may exist in the care of their own patients.”
It was during a lecture three years ago by Banaji that Green came up with the idea of measuring the unconscious bias of physicians by using a test Banaji had helped develop .
Green and his colleagues decided to test residents at Massachusetts General, the Brigham, and Beth Israel Deaconess Medical Center in Boston, as well as at an Atlanta hospital. Residents were told that the study was evaluating the use of heart attack drugs in the emergency room, but not that it was also examining racial bias; 220 trainee doctors were counted in the results.
The residents were first given a narrative describing a male patient who shows up in the emergency room complaining of chest pains. Accompanying the narrative was a computer-generated image of the patient, either a black or white man shown in a hospital gown from the chest up, wearing a neutral facial expression.
The doctors were asked if, based on the information provided, they would diagnose the man as having a heart attack and, if so, whether they would prescribe clot-busting drugs called thrombolytics, commonly used in community hospitals to stabilize patients having heart attacks, and how likely they were to give those drugs.
Study participants were also asked questions designed to determine if they were overtly biased. Answers showed they were not.
Last, the residents took Banaji’s “implicit association test,” which is based on the concept that the more strongly test-takers associate a picture of a white or black patient with a particular concept, say cooperativeness, the faster they will make a match. White, Asian, and Hispanic doctors were faster to make matches between blacks and negative concepts and slower to make matches between blacks and positive ones. The small number of African- American physicians in the study were as likely to show bias against blacks as against whites.
The researchers then compared the implicit association test scores with the decisions about whether to provide the clot- busting medicine and found that doctors whose ratings of African-Americans were most negative were also the least likely to prescribe the drug to blacks.
Another study, scheduled to be presented by a Johns Hopkins medical researcher in October, reaches similar results.
“At the end of the day, even among very well-intentioned people, implicit biases can be both prevalent and in some situations can impact clinical decisions,” said Dr. Amal Trivedi, a healthcare disparities specialist at Brown Medical School who was not involved in the study. “What this study can do is raise awareness of that finding.”
Stephen Smith can be reached at firstname.lastname@example.org.
(Correction: Because of an editing error, headlines on a Page One story Friday about tests finding signs of racial bias in medical care incorrectly described the doctors tested as emergency room trainees. Groups of medical residents were tested.)