Cardiovascular Disease Risk Stratification in Wrist Wearable Devices and e-Health App Users: A Large-Scale Retrospective Study.

Introduction: Wearable devices, including smart wristbands and watches, are often used with e-health applications (apps). The users' characteristics of wrist wearable devices currently lack description, and the cardiovascular disease (CVD) high-risk rate of users remains unknown. Purpose: This study aimed to (1) describe the basic characteristics and habits of users of the "Amazfit Health" app and Huami wrist wearable devices and (2) analyze the proportion and define the population characteristics of users with a high risk of developing CVD. Subjects and Methods: This study included users >18 years of age, residing in mainland China, using the "Amazfit Health" app and Huami wearable devices. Devices data and users' self-reported information were collected in the app. The risk stratification was based on WHO/ISH cardiovascular risk prediction charts for the Western Pacific Region. Subjects with CVD history, total cholesterol ≥8 mmol/L, or ≥10% predicted CVD risk and those with <10% predicted CVD risk were considered to be at high and low risk of developing CVD, respectively. Results: Data were obtained from 80,098 (total users) and 10,866 users (subjects) for risk stratification. The age of the total users and subjects were 45.6 ± 15.4 and 50.7 ± 14.0 years, respectively. The number of male and female users was 50,024, and 30,074 in total users, and 7,284, and 3,582 in subjects, respectively. The body mass index of total users and subjects was 24.0 ± 4.6 kg/m² and 24.6 ± 3.8 kg/m², respectively. By classifying users' residences into first-tier cities, municipalities and provincial capitals, and other areas, the numbers of total users were 20,179, 28,213, and 31,137, and subjects were 2,587, 3,966, and 4,269, respectively. The number of subjects with high CVD risk was 1,161, accounting for 10.7% of all subjects. Conclusions: Users with high CVD risk only accounted for a small proportion of the population of wearable devices users.