Clinician behavior when skin tone affects test results

M Marcella Alsan (Harvard Kennedy School and National Bureau of Economic Research ,) L Liran Einav (Department of Economics, Stanford University) A Amy Finkelstein (Massachusetts Institute of Technology, National Bureau of Economic Research, and J-PAL North America ,) J Jonathan Zhang (Duke University and National Bureau of Economic Research ,)

Abstract

We compare care for Black vs. White patients following pulse oximetry, a widely used device for measuring blood oxygen levels which overestimates oxygen saturation in darker-skinned patients. Black patients are therefore medically more appropriate for follow-up care than White patients with the same pulse oximetry reading. Yet, using data from the Veterans Health Administration on 3.5 million emergency department visits between 2014 and 2018, we find that Black patients systematically receive lower rates of follow-up care than White patients with the same reading. Our findings illustrate how bias in a medical screening device can be propagated and potentially amplified in downstream care.

Article Details

Volume / Issue Vol. 123, Issue 19
Published May 12, 2026
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (4)

M

Marcella Alsan

Harvard Kennedy School and National Bureau of Economic Research ,

L

Liran Einav

Department of Economics, Stanford University

A

Amy Finkelstein

Massachusetts Institute of Technology, National Bureau of Economic Research, and J-PAL North America ,

J

Jonathan Zhang

Duke University and National Bureau of Economic Research ,