Oxygen saturation for the prediction of acute mountain sickness

We read with interest the paper on "Smartwatch measurement of blood oxygen saturation for predicting acute mountain sickness: Diagnostic accuracy and reliability" recently published by Zeng and colleagues in Digital Health. This study demonstrated good reliability and high precision for measuring peripheral oxygen saturation (SpO₂) using Huawei smartwatches during a 1-wk high altitude exposure. In addition, SpO₂ values recorded during the ascent to high altitude were predictive for the development of acute mountain sickness (AMS). Although these findings are valuable and in accordance with previous studies, some additional clarifications would be helpful to better understand the use of SpO₂ and its clinical relevance as an AMS predictor.