COVID-19 patients in racial and ethnic minority groups were delayed in receiving therapies because of an inaccurate reading of oxygen saturation levels, according to a new study.

The study, published Tuesday in JAMA Internal Medicine, found that “overestimation of arterial oxygen saturation levels by pulse oximetry” in COVID-19 patients from racial and ethnic minority groups contributed to “unrecognized or delayed recognition of eligibility to receive COVID-19 therapies.”

“Black and Hispanic patients were more likely to experience unrecognized and delayed recognition of eligibility to receive COVID-19 therapy,” the study also said, adding that such disparities could be the reason for differing COVID-19 outcomes between races.

Throughout the pandemic, data from the Centers for Disease Control and Prevention (CDC) has shown that Black and Hispanic Americans were disproportionately more likely to die of COVID-19. 

In October 2020, the CDC said 24 percent of COVID-19 deaths between May and August of that year were Hispanic or Latino and 19 percent were Black.

But the U.S. population is just 18 percent Hispanic and 12.5 percent Black.

The Food and Drug Administration (FDA) issued a warning for pulse oximeters, which work by shining a red light through a patient’s fingertip, last February. saying that they “may be less accurate in people with dark skin pigmentation.”

“The U.S. Food and Drug Administration is informing patients and health care providers that although pulse oximetry is useful for estimating blood oxygen levels, pulse oximeters have limitations and a risk of inaccuracy under certain circumstances that should be considered,” the FDA said at the time.