Class Action Alleges Certain Fitbits Fail to Accurately Gauge Blood Oxygen Levels of Users with Darker Skin

Jan 24, 2024

by Kelsey McCroskey

A proposed class action alleges certain Fitbit fitness trackers are falsely advertised in that they are unable to accurately measure the blood oxygen (SpO2) levels of users with darker skin.

Want to stay in the loop on class actions that matter to you? Sign up for ClassAction.org's free weekly newsletter here.

The 33-page lawsuit says that even though consumers with darker skin tones pay the same premium price for the fitness trackers as those with lighter skin, the products are nevertheless inaccurate when it comes to measuring SpO2 levels—the percentage of blood that is saturated with oxygen—of users who have darker skin.

Per the suit, this starkly contrasts how Fitbit represents its devices’ blood oxygen-measuring technology, which the company touts as able to gauge a wearer's SpO2 levels by sending pulses of light through the wrist and measuring how much light is absorbed and reflected.

Be sure to scroll down to see which Fitbit smartwatches are mentioned in the lawsuit.

According to the case, the "Health Metrics & SpO2" page on Fitbit.com prominently highlights the fitness trackers’ SpO2 feature "ahead of other health metric technology" incorporated into the devices, such as tech for measuring skin temperature, breathing rate, heart rate variability and other metrics. Another section of the website, aimed at helping users "[u]nderstand your SpO2 levels," includes a handy button that redirects shoppers to lists of Fitbit products that feature the blood oxygen level testing technology, the complaint adds.

The filing argues, however, that Fitbit has misrepresented the devices’ blood oxygen-measuring capabilities—in particular since it has failed to disclose or otherwise disclaim that the SpO2 technology used in the products "inherently discriminates against people of color."

"Despite warning customers that the feature is ‘intended to help you manage your well-being and keep track of your information,’ and is ‘[n]ot intended to diagnose or treat any medical condition,’ [Fitbit] is utterly silent on the racial bias present in the technology," the lawsuit scathes.

Blood oxygen sensors, or pulse oximeters, are typically used in hospitals to gauge blood oxygen levels by way of a device clipped to a patient's fingertip or toe, the suit says. These sensors use pulses of light to measure the volume of oxygen in the wearer's bloodstream based on the way the light is absorbed by the hemoglobin in the blood, the case explains.

However, the complaint reports that a growing number of studies in recent years have exposed defects that plague pulse oximetry when measuring the oxygen levels of patients with darker skin tones. For those with darker skin, the filing says, the pigmentation of the skin absorbs more light from an SpO2 sensor than lighter skin, which can distort the readings and result in the oximeter overestimating the amount of oxygen in the blood.

The lawsuit stresses that this can be dangerous because inaccurate SpO2 readings may hinder necessary, timely care for patients with low blood oxygen levels, a serious condition that can lead to brain, heart and kidney damage.

Unfortunately, the suit says, the "racial bias" inherent in medical pulse oximeter technology "translates over to the smartwatch industry," which boomed during the COVID-19 pandemic as consumers learned that low blood oxygen levels could be a symptom of the virus. Per the case, the growing demand for pulse oximeters spurred the production of wearable devices that include SpO2 technology, including the Fitbits at issue.

The complaint charges that although the marketing of blood oxygen-measuring fitness trackers reasonably leads consumers to believe that the devices’ SpO2 readings "can be trusted," a typical user does not realize that the measurements are "often inaccurate and should not be a replacement for professional testing." The filing contends that this is particularly important given that SpO2 readings taken from the wrist are even less accurate than measurements taken from the fingertip with a traditional pulse oximeter.

Fitbit's director of research, Conor Heneghan, mentioned in a September 2020 Washington Post interview that taking SpO2 measurements on the wrist posed a "pretty hard technical problem," the lawsuit relays. Though Heneghan was open about the products’ testing—which he said included tests on a population in which volunteers with darker skin were "overrepresent[ed]" to ensure the technology was not "skewed toward a particular tone"—the Fitbit exec conspicuously would not disclose the devices’ precise error rate for that research, the suit shares.

Ultimately, the case, citing Duke University assistant professor of biomedical engineering Jessilyn Dunn, emphasizes that, for consumers, there needs to be a "clear distinction" between "toys" and "things that are used for clinical purposes."

Despite the fact that the Fitbits at issue are apparently less capable than advertised of producing accurate blood oxygen levels for users with darker skin, the products are nonetheless sold at a premium price regardless of a buyer's skin tone, the case relays. As a result, consumers with darker skin tones have essentially been "hit with a costly double-whammy: a premium purchase for a worthless product," the suit contends.

One plaintiff in the proposed case against Fitbit, who the suit says has a medical condition that requires her to track her blood oxygen levels, purchased a Fitbit Charge 4 in October 2021 because she believed, based on Fitbit's advertising, that the device would accurately gauge her SpO2 levels, the lawsuit shares.

A second plaintiff claims to have been similarly misled when she bought a Fitbit Versa 2 in July 2021.

The case charges that Fitbit failed to warn the California-based plaintiffs and thousands of other consumers that its fitness trackers suffer from the same "racial bias" that plagues traditional pulse oximetry technology. As the filing tells it, the plaintiffs would not have paid as much for their Fitbits, or bought them at all, had they known about this widespread technical defect.

"The [plaintiffs] and other consumers with dark skin paid a price premium for a device that they believed was capable of SpO2 measurements, and received a Fitness Tracker of a lower quality than did their lighter-skinned counterparts," the complaint alleges.

Other smartwatch companies have faced litigation recently as well, the case notes. For example, Apple was hit with a proposed class action last December in which a consumer alleged the company had misleadingly marketed the SpO2 technology in the Apple Watch, the filing relays.

The suit states that the Fitbit products at issue include the Fitbit Charge 4, Fitbit Charge 5, Fitbit Inspire 3, Fitbit Ionic, Fitbit Luxe, Fitbit Sense series and Fitbit Versa series.

The case looks to represent anyone in the United States with dark skin who purchased any Fitbit device listed on this page at any time since June 2, 2019.

Normally, you don't need to do anything to join or sign up for a class action lawsuit when it's first filed. The time to act is usually if and when a lawsuit reaches a settlement, at which time the people covered by the deal—known as class members—may be notified directly via email or regular mail with instructions on what to do next and details about their legal rights.

Remember, it can often take months or even years for a class action lawsuit to be resolved.

If you think your Fitbit device is inaccurately tracking your blood oxygen levels, or you simply want to stay in the loop on class action lawsuit and settlement news, sign up for ClassAction.org's free weekly newsletter.

This browser does not support PDFs. Please download the PDF to view it: Download PDF.

Camp Lejeune residents now have the opportunity to claim compensation for harm suffered from contaminated water.

Read more here: Camp Lejeune Lawsuit Claims

Stay Current

New cases and investigations, settlement deadlines, and news straight to your inbox.

Kelsey works primarily on ClassAction.org's newswire, reporting on cases as they happen.

ClassAction.org is a group of online professionals (designers, developers and writers) with years of experience in the legal industry.

Before commenting, please review our comment policy.