Faulty pulse oximeter readings delayed life-saving treatments for Black COVID-19 patients, research finds

• A medical device that measures blood oxygen levels doesn't work as well for Black and Hispanic COVID-19 patients.
• A new study found inaccurate blood oxygen level readings led to delayed care for Black and Hispanic patients.

A device that measures blood oxygen levels was more likely to give inaccurate readings for Black COVID-19 patients, resulting in delayed care, according to a new study.

The analysis, published in The Journal of the American Medical Association on May 31, found pulse oximeters overestimated the blood oxygen levels in Black, Hispanic, and Asian COVID-19 patients.

Due to faulty oximeter readings, non-white patients were more likely to receive delayed Covid-19 treatments like dexamethasone or remdesivir, which can help reduce death and hospitalizations.

"There are patients that probably should have had these therapies, and the majority were Black patients," Tianshi David Wu, an assistant professor of medicine at Baylor College of Medicine and co-lead author of the new study told Stat.

"These are likely patients who were seen in emergency rooms and sent home," he said.

Pulse oximeters are more likely to give incorrect readings to Black and Hispanic patients

A pulse oximeter is a small device that clips to the finger to measure how much oxygen the heart and lungs are sending to the body. The device uses light beams to measure oxygen saturation of the blood and pulse rate.

Pulse oximeters became popular during the COVID-19 pandemic, as coronavirus can cause a decrease in blood oxygen levels.

But the devices are imperfect, with a margin of error between 2% to 4%. The rate of errors is particularly bad for Black people; a 2020 study from the University of Michigan suggested Black patients are three times more likely to experience pulse oximeter errors.

In the recent analysis, Dr. Ashraf Fawzy, an assistant professor at Johns Hopkins, built upon the University of Michigan's findings with his team to determine if pulse oximeter readings delayed care for Black and Hispanic COVID-19 patients.

The study found pulse oximeter readings overestimated blood oxygen levels by 1.2% in Black patients and 1.1% in Hispanic patients.

Black patients had to wait longer to get access to COVID-19 treatments

The researchers determined the time it took for patients to get care by looking at when they recorded an oxygen saturation of 94% or less or were put on oxygen support. Those two factors determined whether patients could receive life-saving COVID-19 treatments dexamethasone or remdesivir, according to federal guidelines.

Doctors were less likely to recommend dexamethasone or remdesivir to Black and Hispanic patients due to faulty results from pulse oximeter readings, the study found. Specifically, Black patients were 29% less likely to receive the treatment recommendation, and Hispanic patients were 23% less likely.

Black patients who eventually did receive treatment eligibility had to wait one hour longer than white patients. Doctors did not recognize treatment eligibility at all for 451 patients, most of whom were Black.

Fawzy said both patients and practitioners should rely more heavily on more precise blood testing when measuring blood oxygen levels. Patients who think their pulse oximeter readings could be off should feel empowered to ask for more tests from their doctors.

"Awareness is certainly the most important piece of the puzzle here until we get a durable solution, which is changing the pulse oximeters to be more accurate," Fawzy said.