Wearable devices may be less accurate for detecting heart rate and rhythm in individuals with darker skin tones, according to research presented at the American College of Cardiology (ACC) 71st Annual Scientific Session & Expo, from April 2-4, 2022, in Washington, DC.

Investigators conducted a systematic review to evaluate the accuracy of cardiac data from wrist-worn wearable devices in participants with varying skin tones.

Embase, MEDLINE, CINAHL, and Cochrane databases were searched from inception to July 28, 2021, for original studies that stratified heart rate and rhythm data obtained via consumer wearable technology based on participants’ race and/or skin tone. Skin tone was assessed according to Fitzpatrick score (range, 1-6).

The investigators included 10 studies comprising 469 participants; 6 studies (n=293) reported frequency-weighted Fitzpatrick scores (mean, 3.5).

Overall, 4 of 10 studies reported a significant decrease in the accuracy of heart rate measurement with wearable devices among darker-skinned individuals vs those with lighter skin tones and/or having undergone gold-standard measurements such as electrocardiogram (ECG) or chest strap monitoring.

In addition, 1 study reported that wearable devices recorded significantly fewer data points for patients with darker skin tones, despite no discrepancy in heart rate accuracy. Furthermore, 1 study assessed ECG changes and reported a significant decrease in the accuracy of the R-R interval measurement compared with ECG data in participants with dark skin (r=0.98, P <.05).

The investigators noted that their research was limited by the relatively small number of relevant published studies and variability in the populations, devices, and outcomes assessed in the different studies.

“Early evidence suggests that wearable devices may be less accurate for detection of both heart rate and rhythm in participants with darker skin tones,” stated the study authors. “Further higher quality evidence is needed, involving consistent stratification of participants by race and/or skin tone, to characterize potential racial bias in consumer devices.”

Reference

Koerber D, Khan S, Shamsheri T, Kirubarajan A, Mehta S. The effect of skin tone on accuracy of heart rate measurement in wearable devices: a systematic review. Presented at: American College of Cardiology 71st Annual Scientific Session & Expo; April 2-4, 2022; Washington, DC. Abstract Number: 22-A-11023-ACC. How Accurate Is Smartwatch Heart Data? It Depends on Your Skin Tone. News Release. Washington, DC. March 24, 2022.