Abstract

Alongside rapid economic, social and technological growth, communities are becoming more urbanized. This causes changes in people’s behavior, such as a shift in transportation style from walking or riding a bicycle to using a motor vehicle. Work behavior changes to a sedentary state, such as sitting and using a computer for long periods of time, resulting in insufficient physical activity levels. Smart watches can be used for many applications such as phone calls, steps per day data storage, heart rate detection and tracking for physical activity and exercise patterns. It is a fitness device that tracks physical activity in real time. A low-cost smartwatch offers the potential to promote physical activity (PA) and health in daily living by enabling self-monitoring of personal activity and obtaining feedback based on activity measures. It has an impressive amount of potential to improve personal PA and health behaviors. These devices are not only used by users to monitor their own levels of PA, but also by researchers to track the behavior of subjects. Therefore, it is important to explore how accurate smartwatches are at tracking PA. This study aimed to assess the validity of popular consumer-wearable activity trackers and their ability to estimate steps. Accelerometer data was collected with a smartwatch, then the data obtained was compared with a pedometer activity monitor. Participants were 18-25 years old (n = 50). The participants wore a smartwatch (Xiaomi Mi Band 4 smartwatch) on the non-dominant wrist and wore a pedometer (Yamax Digi-Walker model CW-700/701) on the edge of the skirt or trousers on the same hip as the smartwatch. Participants were required to wear both devices all day at least 10 hours a day, except for when showering or sleeping, and at the same time for 7 days or at least 3 days a week, for instance two weekdays and a weekend day. Participants were permitted to remove their smartwatch during the day, but it must have been removed at the same time as the pedometer. The researcher telephoned participants every other day to note their wearing time and walking count. After 7 days of data collection, data were analyzed by using Intraclass Correlation Coefficient: (ICC) statistics and Bland-Altman plots to test the validity of the smartwatch. Data from 50 participants found that the mean daily number of steps recorded via smartwatch and pedometer were 4,002 and 4,684, respectively. The difference between the two devices was 682 ± 319 steps/day, which was a statistically significant difference (p-value = 0.035). The result of the validity test (ICC) was 0.95 (p-value = 0.001) (very good correlation), and Bland-Altman plots showed 95% limits of agreement with the CI ranging from 498.08 to 866.54 and a mean difference of 682.31 with most of the data (94%) found to be within a very good level of agreement. The smartwatch (Xiaomi Mi Band 4) has a very good level of validity compared to a pedometer for measuring the number of steps per day, ICC = 0.95, p = 0.001.