Pulse oximeters, small devices clipped onto the finger to measure oxygen levels in the blood, have become essential tools in healthcare, especially during the COVID-19 pandemic. They help identify oxygen deprivation, known as hypoxia, which can indicate severe respiratory or cardiac issues. However, recent studies have uncovered a troubling flaw in pulse oximeters—they may provide inaccurate readings for people of color, potentially delaying critical medical intervention.
This issue has caught the attention of the U.S. Food and Drug Administration (FDA), which is now working to address these disparities and ensure pulse oximeters deliver reliable results for everyone, regardless of skin tone. This article explores how pulse oximeters work, the challenges they pose for people of color, and the steps being taken by the FDA to rectify this situation.
How Do Pulse Oximeters Work?
Pulse oximeters use light to measure the oxygen saturation in a person’s blood. The device emits light beams that pass through the fingertip, and a sensor detects how much light is absorbed by the blood. Oxygenated and deoxygenated blood absorb light differently, and the device calculates the oxygen saturation based on this difference.
A reading of 95% or higher is generally considered normal, while levels below 90% indicate hypoxia, a potentially life-threatening condition requiring immediate medical attention.
The Problem: Inaccuracies in People of Color
Recent research has shown that pulse oximeters may overestimate oxygen levels in people with darker skin tones. This issue arises because melanin, the pigment responsible for skin color, affects how light is absorbed. Darker skin can interfere with the device’s ability to accurately measure oxygen levels, leading to a higher likelihood of false-normal readings.
Key Studies Highlighting the Problem
- 2020 Study in the New England Journal of Medicine:
This study found that Black patients were nearly three times more likely than white patients to have undetected low oxygen levels when using pulse oximeters. - 2022 Research from JAMA Internal Medicine:
This study revealed similar disparities in Hispanic and Asian patients, indicating that the issue is not limited to Black individuals.
Impact of Inaccurate Readings
False-normal readings can delay the diagnosis and treatment of critical conditions like:
- Severe COVID-19 and pneumonia
- Chronic obstructive pulmonary disease (COPD)
- Heart failure
Delayed treatment can result in worse health outcomes, including prolonged hospital stays, increased morbidity, and even preventable deaths.
FDA’s Response: Striving for Equity in Medical Devices
The FDA has acknowledged these disparities and is taking steps to ensure pulse oximeters are equitable and accurate for all users. Here’s what the agency is doing:
1. Reviewing Device Standards
The FDA is revisiting the standards for pulse oximeter approval, which were last updated decades ago. Current standards may not adequately account for skin tone variations.
2. Collaborating with Researchers
The FDA is working with scientists and medical experts to study how skin pigmentation affects pulse oximeter accuracy. These findings will inform updated testing and manufacturing guidelines.
3. Mandating Diverse Testing
Manufacturers may soon be required to test pulse oximeters on individuals with a wide range of skin tones during the development process. This would help identify potential biases before devices reach the market.
4. Educating Healthcare Providers
The FDA is emphasizing the need for caution when interpreting pulse oximeter readings, particularly for patients of color. Clinicians are being urged to use additional diagnostic tools and not rely solely on pulse oximeter data.
Challenges in Addressing the Issue
While the FDA’s efforts are commendable, several challenges remain:
- Lack of Regulation for Consumer Devices
Many pulse oximeters sold online or in pharmacies are not FDA-approved. These devices are often less accurate than their clinical counterparts, and the problem of racial bias may be even more pronounced. - Limited Awareness
Many healthcare providers and patients are unaware of the potential inaccuracies in pulse oximeter readings for people of color. This lack of awareness can lead to over-reliance on flawed data. - Technological Hurdles
Developing pulse oximeters that are accurate for all skin tones requires significant technological innovation and investment, which may slow down the implementation of new standards.
The Broader Implications of Medical Bias
The issues with pulse oximeters are part of a larger problem of racial bias in medical devices and healthcare. Many medical technologies, from heart rate monitors to spirometers, have been found to perform less accurately in people of color.
These biases often stem from the lack of diversity in clinical trials and testing during the development phase. For instance:
- Spirometers: These devices measure lung function but are calibrated differently for Black patients based on outdated assumptions about racial differences in lung capacity.
- Thermometers: Some infrared thermometers have been found to provide less accurate readings for people with darker skin.
Addressing the flaws in pulse oximeters could set a precedent for improving equity in medical technology as a whole.
What Can Be Done Now?
While the FDA works on long-term solutions, there are steps that healthcare providers and patients can take in the interim:
For Healthcare Providers
- Use Multiple Diagnostic Tools: Combine pulse oximeter readings with arterial blood gas tests for a more accurate assessment of oxygen levels.
- Be Aware of Bias: Consider the potential for inaccuracies when interpreting readings, particularly for patients of color.
- Educate Patients: Inform patients about the limitations of pulse oximeters and encourage them to seek medical attention if symptoms persist, regardless of device readings.
For Patients
- Monitor Symptoms: Pay attention to physical signs of low oxygen, such as shortness of breath, chest pain, or bluish lips, rather than relying solely on a device.
- Invest in Reliable Devices: Look for FDA-approved pulse oximeters and avoid unregulated consumer models.
- Advocate for Change: Support initiatives that call for greater diversity in medical research and device development.
The Future of Pulse Oximeters
Emerging technologies offer hope for more equitable pulse oximeters. Some researchers are exploring the use of multi-wavelength sensors, which can account for skin tone variations more effectively. Others are integrating artificial intelligence to improve accuracy and reduce bias.
The FDA’s actions to address racial disparities in pulse oximeters could also pave the way for broader reforms in the medical device industry. By prioritizing diversity and inclusivity in research and development, we can ensure that future healthcare technologies serve everyone equally.
Pulse oximeters have been lifesaving tools in modern medicine, but their limitations highlight the urgent need for equity in healthcare technology. For people of color, inaccurate readings can mean delayed treatment and worse health outcomes, underscoring the importance of addressing these disparities.
The FDA’s commitment to revising standards and promoting diverse testing is a crucial step forward. However, lasting change will require collaboration among regulators, manufacturers, healthcare providers, and patients.
By recognizing and addressing bias in medical devices, we can move closer to a healthcare system that truly serves all individuals, regardless of their skin tone. The journey to equitable healthcare is long, but with continued efforts, it is undoubtedly achievable.
