Racial Bias in Pulse Oximetry Measurement
Overview
This project was led by Michael Sjoding, an assistant professor of pulmonary and critical care medicine at Michigan Medicine, co-author in the CHEST publication, and leading voice for pulse oximetry reform. Dr. Sjoding and team utilized AI & Digital Health Innovation’s Research Data Warehouse, among other resources, tools and data for their research.
Their defining paper, published in the New England Journal of Medicine in December 2020, reported results from a similar analysis of occult hypoxemia rates in a group of patients receiving a wide-range of respiratory support; The study found that Black patients had nearly three times the frequency of occult hypoxemia that was not detected by pulse oximetry as White patients.
The pulse oximeter, a device that first came to market in the 1980s, is an essential tool used to estimate patients' oxygen levels at home or in clinics and hospitals. The devices help guide critical medical decisions such as whether a patient needs admission to the hospital or should be provided supplemental oxygen. Pulse oximeters have been widely used to measure the oxygen levels of patients during the COVID-19 pandemic.
Given the widespread use of pulse oximeters for medical decision-making, it is critical that these devices work equitably for everyone. When pulse oximeters fail to identify someone with very low oxygen levels in the hospital, that person is less likely to receive supplemental oxygen and life-saving medical treatment. It is also associated with an increased risk of organ failure and a higher likelihood of dying in the hospital.
Previous studies dating back to 1990 had raised concerns that pulse oximeters could be less accurate in individuals with darkly pigmented skin, the inaccuracies thought to be due to differences in the amount of melanin in the skin. The amount of melanin may affect how light is transmitted by the pulse oximeter through the skin to measure oxygen levels.
Motivated by their experience using pulse oximeters to care for critically ill patients during the first wave of the COVID-19 pandemic, this U-M team studied whether pulse oximeters are less accurate in Black patients compared to White patients in Critically ill adults in the intensive care unit, hospitalized children, and hospitalized Veterans. Oxygen level readings on pulse oximeters were compared to those measured by arterial blood gas—a more accurate measure obtained via a painful procedure involving drawing blood from an artery.
Since this research was originally published, much more scholarship has been generated on this crucial issue, from researchers inside U-M and across the country. Several US Senators flagged the pulse oximeter issues as a concern that needed to be urgently addressed, and the FDA has had several hearings related to concerns around the pulse oximeter and racial bias.
Finally, in January 2025, the FDA released new draft guidance with updated standards for pre-market evaluation of pulse oximeters. The proposed changes include increasing the number of study subjects from 10 to 150 and performing additional testing to ensure there are no performance differences between subjects with dark and light skin tone.
Here some more background on this update:
https://www.cnn.com/2025/01/06/health/fda-pulse-oximeters-draft-guidance/index.html
Principal Investigator(s)
Michael W. Sjoding, M.D.
Thomas S. Valley, M.D.