Abstract
Decreased oxygen saturation (SO2) at high altitude is associated with potentially life-threatening diseases, e.g., high-altitude pulmonary edema. Wearable devices that allow continuous monitoring of peripheral oxygen saturation (SpO2), such as the Garmin Fēnix® 5X Plus (GAR), might provide early detection to prevent hypoxia-induced diseases. We therefore aimed to validate GAR-derived SpO2 readings at 4559 m. SpO2 was measured with GAR and the medically certified Covidien Nellcor SpO2 monitor (COV) at six time points in 13 healthy lowlanders after a rapid ascent from 1130 m to 4559 m. Arterial blood gas (ABG) analysis served as the criterion measure and was conducted at four of the six time points with the Radiometer ABL 90 Flex. Validity was assessed by intraclass correlation coefficients (ICCs), mean absolute percentage error (MAPE), and Bland–Altman plots. Mean (±SD) SO2, including all time points at 4559 m, was 85.2 ± 6.2% with GAR, 81.0 ± 9.4% with COV, and 75.0 ± 9.5% with ABG. Validity of GAR was low, as indicated by the ICC (0.549), the MAPE (9.77%), the mean SO2 difference (7.0%), and the wide limits of agreement (−6.5; 20.5%) vs. ABG. Validity of COV was good, as indicated by the ICC (0.883), the MAPE (6.15%), and the mean SO2 difference (0.1%) vs. ABG. The GAR device demonstrated poor validity and cannot be recommended for monitoring SpO2 at high altitude.
Highlights
Wearable devices are increasingly used to monitor physiological biomarkers [1]
The aim of this study was to evaluate the validity of the Garmin Fenix® 5X Plusderived SpO2 readings at 4559 m
Lauterbach et al evaluated the accuracy of SpO2 readings derived from the same Garmin device as used in the present study at simulated altitudes up to 3660 m
Summary
Wearable devices are increasingly used to monitor physiological biomarkers [1]. If certified by the relevant regulatory authorities, they can be used to monitor and/or diagnose diseases, e.g., abnormal heart conditions, hypertension, and diabetes [2]. With the increasing demand for such devices, commercially available wearables may be used to assess the risk of potentially life-threatening diseases despite not being intended for such purposes and despite not having received medical certification. This means that these devices are being used without having undergone the rigorous validity testing required for certification as a medical device. Oxygen saturation (SO2) is reduced [3,4] This condition is associated with a group of diseases categorized as high-altitude illnesses. It is worth noting that SpO2 is useful for risk assessment and providing an early warning of deterioration in patients suffering from COVID-19 [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
