Racial Differences in Pulse Oximeter Performance May Lead to Inequity

On July 11, 2022, researchers published an article in JAMA Internal Medicine noting racial differences in pulse oximeter performance. Researchers also postulated that these discrepancies might be contributing to worsening healthcare inequity.  

Pulse oximetry was first developed in 1974 and has since been used as a transcutaneous way to monitor arterial hemoglobin oxygen saturation. Despite the wide use of pulse oximetry, the JAMA publication acknowledges that surface pigmentations from nail polish to skin tone can alter readings.  

A retrospective cohort study was conducted using the Medical Information Mart for Intensive Care data. This 3069-patient study included Black, White, Asian, and Hispanic individuals.  

The median blood hemoglobin saturation for Black patients was 95%, while that for White patients was 96%. Furthermore, Asian and Hispanic patients had a median blood hemoglobin saturation similar to white patients at 96% and 96.2%, respectively.  

Despite having a lower median blood hemoglobin saturation, Black patients had a 1% higher pulse oximetry reading than White patients. Similarly, Hispanic and Asian patients also had higher pulse oximetry readings than white patients.  

When examining median oxygen delivery rates, Black and Hispanic patients had a 0.2 L/minute lower delivery rate than White patients. Asian patient delivery rates were 0.4 L/minute less than White patients.  

After the adjustment for confounders, the researchers concluded that non-White patients received less supplemental oxygen.  

Diversity in clinical trials and medical device development has historically been lacking. This lack of diversity may contribute to the lack of health equity.  

According to the CDC, “racial and ethnic minority groups, throughout the United States, experience higher rates of illness and death across a wide range of health conditions, including diabetes, hypertension, obesity, asthma, and heart disease, when compared to their White counterparts.” 

Due to the racial differences in pulse oximeter performances, the investigators recommended adjusting how pulse oximeter data is used. Adjustments like those recommended may help begin closing the widening healthcare gap.  

“Our findings present a unique and compelling opportunity to improve equity through device reengineering and by reevaluating how data are interpreted. However, this should be done with caution, as some past attempts to correct for race and ethnicity in algorithms have exacerbated disparities and are subject to ethical concerns, such as those leading to the removal of the African American race coefficient from the Chronic Kidney Disease Epidemiology Collaboration estimated glomerular filtration formula in 2021,” stated the researchers in the publication.  

As further research on how pulse oximetry performance is impacted by race and skin tone is done, clinicians and medical device developers will determine how it may alter diagnostics and patient care.