1999 --- Listening to Patient's Heartbeat with Stethoscope --- Image by © Michael Keller/CORBIS

Does Diversity Matter for Health? Experimental Evidence from Oakland

Marcella Alsan, Owen Garrick, Grant C. Graziani

NBER Working Paper No. 24787
Issued in June 2018
NBER Program(s):Health Economics

We study the effect of diversity in the physician workforce on the demand for preventive care among African-American men. Black men have the lowest life expectancy of any major demographic group in the U.S., and much of the disadvantage is due to chronic diseases which are amenable to primary and secondary prevention.

In a field experiment in Oakland, California, we randomize black men to black or non-black male medical doctors and to incentives for one of the five offered preventives — the flu vaccine. We use a two-stage design, measuring decisions about cardiovascular screening and the flu vaccine before (ex ante) and after (ex post) meeting their assigned doctor.

Black men select a similar number of preventives in the ex-ante stage, but are much more likely to select every preventive service, particularly invasive services, once meeting with a doctor who is the same race. The effects are most pronounced for men who mistrust the medical system and for those who experienced greater hassle costs associated with their visit.

Subjects are more likely to talk with a black doctor about their health problems and black doctors are more likely to write additional notes about the subjects. The results are most consistent with better patient-doctor communication during the encounter rather than differential quality of doctors or discrimination. Our findings suggest black doctors could help reduce cardiovascular mortality by 16 deaths per 100,000 per year — leading to a 19% reduction in the black-white male gap in cardiovascular mortality.

In short they found the following, which continue to support the value of a diverse healthcare workforce:

1)  Black male patients were more willing to receive preventive healthcare services (Flu shot, cholesterol check, HgA1c etc) from Black doctors compared to non-Black doctors;

2)  Black male patients were more likely to talk with a Black doctor about their health problems;

3)  Black doctors engaged more with the Black male patients compared to the non-Black doctors; and

4)  Our findings suggest Black doctors could help reduce cardiovascular mortality by 16 deaths per 100,000 per year — leading to a 19% reduction in the black-white male gap in cardiovascular mortality