A 2020 paper in Proceedings of the National Academy of Sciences reported that Black newborns cared for by Black physicians had lower in-hospital mortality in a dataset of 1.8 million Florida births from 1992 through 2015 (Greenwood et al., PMID 32817561). That finding was widely reported in public conversation about racial concordance in clinical care. A 2024 replication in the same journal, by George Borjas and Robert VerBruggen, reanalyzed the same Florida dataset and reported that the concordance effect on newborn mortality became statistically insignificant once very-low birth weight was included as a covariate along with hospital and physician fixed effects (PMID 39284046).
Neither paper is a randomized trial. Both are peer-reviewed in the same journal. The honest reading is that the 2020 observational signal did not survive the most rigorous published replication attempt on its own data.
What the Greenwood paper actually reported
The Greenwood team analyzed Florida hospital discharge records covering 1.8 million births over 23 years and controlled for hospital and physician fixed effects plus 65 ICD-code comorbidity indicators. They reported that Black newborns cared for by Black physicians had a significant improvement in in-hospital mortality compared to Black newborns cared for by non-Black physicians. The effect was concentrated in complicated deliveries and in hospitals that delivered more Black babies. The paper did not find an equivalent concordance benefit in maternal mortality; the effect was specific to newborn survival.
What the Borjas and VerBruggen replication changed
The 2024 replication used the same Florida dataset and tested whether adding very-low birth weight (under 1,500 grams) as a separate covariate altered the estimated effect. It did. The authors reported that the concordance coefficient fell to near zero and statistically insignificant when very-low birth weight, hospital fixed effects, and physician fixed effects were included together. Their interpretation was that the original 2020 effect was explained by an association between physician race and the very-low-birth-weight caseload that hospitals route to specific physicians, rather than by concordance itself.
The Alsan 2019 Oakland trial still holds
A 2019 field experiment by Marcella Alsan, Owen Garrick, and Grant Graziani in the American Economic Review randomly assigned 1,300 Black men in Oakland, California, to primary care physicians who were either Black or non-Black, and measured preventive-service uptake. Black men assigned to Black doctors were 47 percent more likely to accept preventive services in aggregate, with the effect driven by stronger communication in the clinical encounter (Alsan et al., American Economic Review 2019). The authors estimated that this concordance effect on preventive uptake could reduce the Black-white male gap in cardiovascular mortality by 19 percent through the pathway of better screening adherence.
That finding is randomized. It measures behavior, not mortality directly. It is the evidence in the concordance literature that comes from random assignment rather than observational inference.
Two separate claims often collapse into one in public coverage
The first claim is that Black patients live longer when cared for by Black clinicians. That claim traces mostly to observational data that has not held up in the most rigorous replication on its own dataset. The second claim is that Black patients accept more preventive care when cared for by Black clinicians. That claim has randomized support and reaches mortality only through the inference that better preventive care produces better mortality outcomes.
When a piece reports that "having a Black doctor saves Black lives," the underlying evidence is either the contested Greenwood 2020 observational effect (weak support) or the Alsan 2019 behavioral effect with a downstream mortality inference (moderate support). "Saves lives" is not a statement either paper supports directly.
What this means if you are a Black patient or a journalist
If you are a Black patient, the randomized evidence says seeking out a Black clinician is likely to improve your engagement with preventive services and your communication with the clinical team. That is not the same as a guarantee of better mortality outcomes. If you are a journalist or researcher covering this beat, the honest framing going forward is that the Greenwood 2020 observational mortality claim is contested in the published record and the randomized evidence in this literature is on behavior, not mortality.
