The devices commonly used to do this – known as a pulse oximeter – are easy to use. It hangs on your fingertips like a clothespin.
Even the hardware is biased away
But these devices recorded that some dark-skinned patients are enjoying better health than they really are, and perhaps this is what led to people being denied treatment in the hospital.
The Economist said:The EconomistA work published last year in the New England Journal of Medicine, which studied more than 10,000 patients in the United States; It was suggested that pulse oximeters use blood oxygen saturation to an excessive degree in blacks more than whites.
The magazine explained that a person who is in good health has an oxygen saturation rate between 92 and 96%. And in this work, some patients who scored this level on pulse oximetry had a true saturation of less than 88%.
For black participants, this occurred in 12% of cases, 3 times the rate reported for white participants. As study lead Michael Sjöding of the University of Michigan observed, this difference marked a watershed between hospitalization and returning home.
The magazine stated that Dr. Sojuding’s investigations are not the only evidence of this bias. Work indicating problems with pulse oximeters dates back to 1999.
On February 19, after some media attention and a letter to the Food and Drug Administration from 3 senators; That agency issued a warning that “pulse oximeters are flawed, and may lack accuracy under certain circumstances that must be taken into account.”
But the broader idea is that medical technology must be designed from the start to be free from such bias, and unfortunately it is not. They were designed by white men and tested on white men; So it’s no surprise that it works best for white men.
Pulse oximeters – invented in the 1970s and adapted for commercial use in the 1980s – are a classic example of this. It works by passing two beams of light, one red and one infrared, through the tissue of the finger and then calculating the amount of everything that is absorbed.
The oxygenated and deoxygenated hemoglobin absorbs these frequencies differently, which means that the percentage of oxygen saturation in a person’s blood can be determined by comparing the strength of the two beams after they pass through that patient’s finger.
It is clear that dark skin absorbs the incident light more than white skin, which weakens the signal, and may absorb one ray more than the other; Therefore, unless this calibration is performed on both of them the result may be biased.
Despite its history of errors, pulse oximetry is a mainstay in hospitals. The arterial blood gas measurement is intended for seriously ill patients.
Even before Covid-19, doctors routinely used pulse oximeters to determine who was admitted to hospital, monitor patients’ health, and make decisions about their treatment.
But the pulse oximeter is not the only example of bias. Another scandal is a medical algorithm used by more than 100 million Americans annually to allocate scarce resources to those who need them most.
A study published in 2019 showed that this program prioritized white patients over black patients because it used people’s past medical expenditures as a guide to their current medical needs.
Because black patients typically spend less on medical care due to lack of access and racial bias in treatment, they typically have lower prior expenditures than white patients with similar medical requirements, and white patients are discriminated against.
Bias against women
The magazine explained that race is not the only source of racial prejudice; Women often encounter medical problems when seeking treatment. For example, procedures such as hip transplantation and heart surgery that are performed on women are more likely to fail than men.
A 2013 study published in the Journal of the American Medical Association found that women in the four American regions studied by the authors were 29% more likely to have a hip implant failure within 3 years of hip replacements.
Another study published in 2019 found that women are twice as likely to suffer complications from implantable heart devices, such as pacemakers, within 90 days of their implantation.
This is due to the device makers’ failure to recognize physical differences, especially in size, between male and female bodies. This makes women more vulnerable to health complications. So the devices should be tested on a larger scale in order not to remain the preserve of white males.
Since 1993, Congress has directed the nation’s National Institutes of Health to require women and non-white people to be included in clinical trials, and FDA guidelines encourage studies to obtain “sufficient numbers” of participants to conduct analyzes by gender or race.
But after decades of mentoring, the representation of non-white people and women is still inadequate. An analysis published in 2019 found that women accounted for less than 30% of the number of participants in 15% of the studies conducted in 2015. 13% of the population of America – they account for 10% or less of the number of participants in the study.