The Medical Device That May Lead to Harm in People of Color

Several biological indicators used to assess our physical health have come into question; BMI, BP, temperature, and oxygen readings. All of them may need revamping or a rethinking of ranges rather than rigid numbers, but we question one because of the device used to measure it.

Racial bias prevents many people from attending adequate schools, entering promising careers, and accessing adequate healthcare. This bias also affects where they can find suitable housing, and that housing may contribute to health difficulties brought on by pollution or vermin infestation. The situation, undeniably, is untenable, and anyone who believes in human rights will find each of these impediments anathema.

All the above is clear, but taking the situation two steps further will reveal the hidden extent of the potential damage raining down on anyone who is a victim of this bias. And, most disturbing, this further damage to health happens in the medical realm.

Socioeconomic factors lead to health risks such as asthma, and the need for ongoing, accurate treatment for asthma is mostly with inhalers. The condition is so severe that frequent emergency treatment is sought. Compared with white people with asthma, African American people with asthma are five times more likely to visit the emergency room for symptoms.

One of the inhalers of choice for asthma is albuterol, and here, again, there is a problem with treatment. A study of over 1,400 children revealed a genetic lack of appropriate response to this drug in some patients. And problems in sampling were apparent. We and others have documented the implications and challenges posed by the lack of non-European study populations in biomedical research. Sampling bias is at the heart of one major problem in device engineering.

Once asthma treatment is sought, there still needs to be a resolution to the underlying measurement problem. While in the ER, how is the oxygen level of these patients determined? The usual initial route is to get a quick level using an oximeter slipped on a finger. It’s a rapid and supposedly accurate measure of how much oxygen the patient has in their blood; vital information.

Who questions the oximeter readings? The assumption is that the task is accurate because the device is FDA approved, made by a reputable company, and has been used for years in hospitals. But that conclusion is patently false.

The validity of the readings was made primarily on persons of European descent. How accurate would they be on anyone who did not meet that criterion? The answer would seem obvious.

Studies dating back to 2005 show pulse oximeters tend to overestimate the amount of oxygen a patient with darker skin may actually have in their blood. It’s simple physics: Melanin in skin absorbs some of the light the devices analyze to make their readings. The darker the skin, the more melanin there is, and the less light passes through.

If the readings are wrong, how does that have an impact on treatment? Again, no question that there is a bias in oxygen levels leading to changes in medical care.

The FDA issued an alert on oximeters, but did everyone dispose of their older, inaccurate devices in healthcare and the home? Other factors affect these readings, including poor circulation, skin pigmentation, skin thickness, skin temperature, current tobacco use, and use of fingernail polish.

NASA had developed guidelines and devices for more accurately measuring blood oxygen, but the corporation involved in it changed its marketing direction and the device was dropped.

We know that the disturbing use of oximeters tested in Japan (with a relatively homogenous population) may lead to delays in treatment in persons with darker skin. How is this permissible? It’s not, and the NASA devices should be considered again.