In the U.S., racial and ethnic minorities have higher rates of chronic disease, obesity, and premature death than white people. Black patients in particular have among the worst health outcomes, experiencing higher rates of hypertension and stroke. And black men have the lowest life expectancy of any demographic group, living on average 4.5 fewer years than white men.
A number of factors contribute to these health disparities, but one problem has been a lack of diversity among physicians. African Americans make up 13% of the U.S. population, but only 4% of U.S. doctors and less than 7% of U.S. medical students. (Of active U.S. doctors in 2013, 48.9% were white, 11.7% were Asian, 4.4% were Hispanic or Latinx, and 0.4% were American Indian or Alaska Native.) Research has found that physicians of color are more likely to treat minority patients and practice in underserved communities. And it has been argued that sharing a racial or cultural background with one’s doctor helps promote communication and trust.
A new NBER study looks at how changing this ratio might improve health outcomes — and save lives. Researchers set up an experiment that randomly assigned black male patients to black or nonblack male doctors, to see whether having a doctor of their race affected patients’ decisions about preventive care. They found that black men seen by black doctors agreed to more, and more invasive, preventive services than those seen by nonblack doctors. And this effect seemed to be driven by better communication and more trust.
Increasing demand for preventive care could go a long way toward improving health. A substantial part of the difference in life expectancy between white and black men is due to chronic diseases that are amenable to prevention. By encouraging more preventative screenings, the researchers calculate, a workforce with more black doctors could help reduce cardiovascular mortality by 16 deaths per 100,000 per year — resulting in a 19% reduction in the black-white male gap in cardiovascular mortality and an 8% decline in the black-white male life expectancy gap.
A Field Experiment in Oakland
The researchers — Drs. Marcella Alsan of Stanford University, Owen Garrick of Bridge Clinical Research, and Grant C. Graziani of the University of California, Berkeley — wanted to conduct a community-based study, so they recruited black men from 20 barbershops and two flea markets in Oakland, California. “These are very special places in the black community,” Dr. Garrick told me. “There’s a wide income, educational, and age range. If you have hair, you’re going to visit the barbershop every week or two.”
They were able to enroll more than 1,300 black men to participate. First, the participants received a monetary ($25) incentive to complete a baseline survey, which asked about socio-demographics, health care, and medical mistrust. Then they received a coupon for a free health screening for blood pressure, BMI, cholesterol, and diabetes at a clinic. They were offered another incentive ($50) to go, as well as a ride if they needed one.
The researchers couldn’t find a freestanding clinic with a mix of black and nonblack doctors to partner with, so they created one themselves. They hired 14 male doctors (eight nonblack and six black) to provide these screenings, telling them that the study — officially called the Oakland Men’s Health Disparities Project — aimed to improve the uptake of preventive health screening services for black men. What they didn’t tell the doctors was that their race was being randomized.
About half of the participants showed up to the clinic for a screening. Those who did tended to be older, have lower self-reported income and health, be unemployed, have less education, and not have a primary care doctor. Once participants got to the clinic and to their private patient room, they were given a tablet showing a photo of their (randomly assigned) doctor, his name, and a list of the services they could select. They saw that two of these screenings, for diabetes and cholesterol, required a finger prick of blood. Then they saw that they could get a flu shot, and some were randomly assigned to see an incentive of $5 or $10 to agree to it.
Participants then talked to their doctor. Doctors were only allowed to provide these five preventive services — all highly recommended, cost-effective interventions — and were told to encourage patients to agree to all of them. During the consultation, patients could revise their selections and have the services done. After the visit, patients filled out a feedback form. Then researchers compared the services provided with the services the men chose before talking to the doctor.
The results were fascinating. In the first stage, before meeting their doctor, participants selected the same number of preventive services, regardless of whether the doctor they saw on the tablet was black. “We hypothesized that if there was aversion, like ‘I just don’t like a doctor of this type,’ that would be elicited at this stage. Because you don’t actually interact with someone yet,” Dr. Alsan said.
But in the second stage, after talking to their doctor, men who met with black doctors elected to receive more preventive services — especially more invasive services that required a blood sample or injection — than men who met with nonblack doctors. This held even controlling for duration of the visit and physician characteristics. “We can only speak to our study and our population. But it was a very striking and strong finding,” Dr. Alsan said.
For example, participants assigned to black doctors were more likely to have their blood pressure and BMI measured than those who saw nonblack doctors. And for invasive tests, only men who saw a black doctor agreed to take up more services than they had initially selected. A participant who saw a black doctor was 20 percentage points (47%) more likely to agree to a diabetes screening and 26 percentage points (72%) more likely to accept a cholesterol screening than those who saw a nonblack doctor.
Men were 10 percentage points (56%) more likely to agree to the flu shot if their doctor was black. “Even among men who had been offered the opportunity to get a $5 or $10 incentive to say yes to the flu shot, some of those men had turned that money down, saying, ‘No, I really don’t want a flu shot. I just don’t want a flu shot,’” Dr. Alsan said. “The African-American doctors were able to convince some of those men who had turned down the money to obtain a flu shot.”
The researchers also found that the effects were most pronounced for men with greater mistrust of the medical system. They were the most reluctant to have services done in the beginning, and they were the most likely to change their minds after talking to a black doctor and to have more services done. This is meaningful, as other research has found that black men are more likely to distrust the U.S. health care system than white men, and that this distrust leads to delayed preventive care and worse outcomes.
Trust and Communication
Why would black men choose more services after seeing a black doctor? Looking at doctor notes, patient feedback, and data from a separate survey, the researchers point to a few pieces of evidence suggesting that better trust and communication between black doctors and black patients was what made the difference.
First, because the study was focused on offering preventive care, as opposed to curative care treating illness, the role of the doctor was mostly limited to explaining the benefits of the preventive services and then providing them. Participants knew this, but they were 10 percentage points (29%) more likely to talk about other health or personal issues with black doctors than with nonblack doctors. And black doctors also wrote longer notes about their patients than nonblack doctors.
Second, the researchers gathered additional data by surveying a similar sample of 1,490 black and white men on doctor preferences. Respondents saw a set of black, white, and Asian male doctors, and selected which doctor they thought was most qualified, which they’d feel more comfortable with, and which was most accessible to them.
Both white and black men thought that doctors of their race were about as qualified as other doctors. There wasn’t a clear sign of preference. “But when it came to communication, when we asked, Which doctor would you feel more comfortable with? Which doctor would understand you the best? That’s when we saw a shift.” Dr. Alsan said. Nearly 65% of black respondents and 70% of white respondents reported that a doctor of the same race would understand their concerns best.
“A lot of our job as doctors is to talk to people, and to understand where they’re coming from,” Dr. Alsan said. “They’re sharing some of the most intimate regions of their lives and their concerns with you.”
Of course, the precise mechanisms here are difficult to pin down, and the researchers acknowledge that other factors besides communication and trust could be at play. They didn’t script doctors’ interactions and weren’t in the room to observe differences in their care. Perhaps black doctors were somehow better-quality, or maybe discrimination played a role. But the evidence they did have doesn’t support these interpretations — on feedback forms, for instance, patients rated both black and nonblack doctors equally positively.
“We think [better communication] is a mechanism behind our results, and we have suggestive findings that support that interpretation. But it would be a great follow-on study to figure out what type of communication [mattered],” Dr. Alsan said. “Seeing what can be taught and what one can learn would be a wonderful next-generation study.”
How Diversity Can Improve Care
This study supports the push to increase diversity in the health care workforce. Many racial and ethnic minority patients seek out doctors of the same background — but access is an issue. The survey found that white men were 20 percentage points more likely than black men to say they could access a doctor of their race.
But the researchers and others advise against interpreting these results to mean that black patients should be treated by black doctors preferentially. “We certainly don’t want people to take away from this that, hey, if you’re not black, you can’t relate to black patients,” Dr. Garrick said. “If anything, you might think, what may I be missing here?”
Dr. Anupam Jena, a physician at MGH and an economist affiliated with NBER, who was not associated with the study, urged similar caution. However, he said, “We should be aware that empathy and understanding of your patient, perhaps through shared experiences, might have an important causal impact on health,” he said.
Dr. Jena noted that what he liked most about the study was that it was so ambitious — it randomized across a large number of patients and set up a separate clinic. He also pointed out that because it focused on preventive care, it’s hard to know whether the findings would generalize to care that is provided to sick patients in need of treatment.
But black men are less likely to seek routine and preventative care than other groups, and increasing their uptake could yield significant health benefits. “Prevention is the unsung hero of medicine,” Dr. Alsan said. “The amount of premature mortality that you can save or spare is quite remarkable with comprehensive preventive intervention.”
And it’s not just prevention. “It’s also much earlier diagnosis and awareness if there is disease,” Dr. Garrick said. “If you look at lower life expectancy for African-American men, there’s a lot of late diagnosis of disease, from prostate cancer to cardiovascular disease. And getting these preventative services doesn’t just help prevent the diseases, in the case of vaccines, but it also serves as more of an early detection, an early warning system, which is one of the big factors impacting minority health and health equity.”