Validation of consumer wearable activity tracker as step measurement in free-living conditions

Different generations of consumer wearable activity trackers are prevalent with the increasing demands in health and physical activity monitor. This pilot study aims to validate one of the consumer wearable activity trackers, the Mi band 2 as a step measurement in free-living conditions. Thirty-one healthy volunteers, aged 23 to 45 with 16 female (52%), wore both Mi band 2 and ActiGraph GT9X Link on their dominant hand’s wrist for seven consecutive days. The validity of the electronic activity devices was assessed objectively by average steps/day using i) Paired sample t-tests; ii) Pearson correlation. In addition, Bland-Altman plots were constructed to visually inspect the data and to assess agreement with the ActiGraph accelerometer. There was a high correlation in steps/day between the reference device, Actigraph accelerometer and Mi Band 2 (r = 0.97, p < 0.001). No significant mean different in steps/ day and no apparent systematic biases in the Bland-Altman plots between step count measurements obtained using the Mi Band 2. Xiaomi Mi Band 2 provided valid step count measurement in the free-living conditions