As the health care system moves toward greater reliance on wearables for health-related data, researchers are raising alarm about the ability of some wearables to provide accurate data for people with darker skin tone.

The deficiency of the wearables, according to an editorial in Sleep Research Society, is derived from the use of photoplethysmographic (PPG) green light signaling, which measures the green light absorption of blood. A darker skin tone, however, may impact the rate of absorption and lead to inaccurate results, assert the editorial authors.

“The reduced accuracy of wearable devices in people with darker skin tones seems to have been known for some time, yet this issue has garnered little attention from the medical community,” explain the authors.

photo of woman stretching on handrails
Inaccurate wearable data will increase structural health disparities for people of color

Notably, to date, at least one study examining a potential bias of wearable devices found “no statistically significant difference in accuracy across skin tones,” but the importance of the issue warrants close consideration.

The potential for inaccurate wearable data based on skin tone is not just an isolated medical issue, according to the researchers, but also connects to broader systemic racism.

“The Black Lives Matter movement is calling for everyone to unveil and dismantle systemic bias throughout society. We challenge the healthcare community to work towards this goal and to ensure that digital health solutions do not reinforce existing disparities in care and access as these devices are increasingly used in research and clinical practice.”

We challenge the healthcare community to work towards this goal and to ensure that digital health solutions do not reinforce existing disparities in care and access as these devices are increasingly used in research and clinical practice.

The editorial outlines 5 action steps for the research community to address the possibility of biased wearable data based on skin tone:

 (1) Directly work with wearables companies to improve upon their effectiveness and consumer reach to support people of color;

(2) Decrease use of the Fitzpatrick scale and increase reporting of more objective, non-offensive, standards of skin tone (Note: The Fitzpatrick scale is a controversial classification of skin types developed in 1975);

(3) Urge companies to advance their technology (e.g. using multiple wavelengths for varying skin tone, improved fit, or using hospital-grade technology);

4) Hold the research community accountable for addressing and reporting bias; and

5) Make sure that people of varying skin tones are included in validation and effectiveness research

Why It Matters

Ensuring accurate wearable data across skin tones is important for many reasons, including:

  1. Black Lives Matter
  2. Wearable data is transitioning from the consumer realm to the medical realm, which means accuracy is critical
  3. People of color are historically underserved by the medical community and report higher rates of chronic disease and adverse health conditions