Pulse oximeter measurements are less accurate among Black, Hispanic and Asian COVID-19 patients compared to white patients. These inaccuracies may have led to minority patients receiving delayed or no treatment, according to a study published May 31 in JAMA Internal Medicine.
The retrospective study involved pulse oximeter readings from 7,126 COVID-19 patients who received care across five hospitals at Baltimore-based Johns Hopkins Health System between March 2020 and November 2020. Of those, 1,216 patients also had arterial blood gas measurements taken, which provide more accurate readings.
Researchers found discrepancies between the arterial blood gas tests and pulse oximeter readings among patients of all races, though they were more pronounced for patients of color. Relative to white patients, pulse oximeter measurements overestimated oxygen levels by 1.2 percentage points among Black patients; 1.1 percentage points among Hispanic patients; and 1.7 percent among Asian patients. While small, the inaccuraccies can have a significant effect on a patient's treatment options, experts told The Wall Street Journal. Across Johns Hopkins Health System, for example, COVID-19 patients with pulse oximeter readings below 94 percent were considered to be severe.
"An inaccurately high oxygen saturation … would disqualify a patient for more aggressive COVID-19 therapies," Tianshi David Wu, MD, study author and assistant professor of medicine at Baylor College of Medicine in Houston told WSJ.
Researchers also used statistical models to estimate the number of patients who may have had oxygen levels indicating severe COVID-19 that weren't recognized as eligible for treatment due to higher pulse oximetry readings. They estimated Black patients were nearly 30 percent less likely than white patients to be recognized for treatment. That figure was 20 percent for Hispanic patients; no significant difference was found for Asian patients.