Table 2. Validity of the Xiaomi Mi Band wristbands for estimating daily physical activity (n = 62).
| Instrument |
Mean (SD) |
Equivalence test (90% CI) |
LOA (95% CI) |
MAE |
MAPE |
ICC (95% CI) |
| Steps (n) |
| ActiGraph wGT3X-BT |
7,066.8 (3622.3) |
-1,060.0, 1060.0 |
- |
- |
- |
- |
| Xiaomi Mi Band 2 |
7,287.0 (4017.2) |
-462.8, 22.3 |
-220.2 (-2461.5, 2021.1) |
791.8 |
12.3 |
0.95 (0.93, 0.97) |
| Xiaomi Mi Band 3 |
7,193.9 (4041.0) |
-392.1, 137.7 |
-127.2 (-2574.8, 2320.4) |
890.6 |
13.6 |
0.95 (0.91, 0.97) |
| Xiaomi Mi Band 4 |
7,544.0 (4124.2) |
-742.4, -212.1 |
-477.2 (-2927.2, 1972.8) |
916.9 |
13.2 |
0.94 (0.90, 0.97) |
| Xiaomi Mi Band 5 |
7,441.9 (4068.2) |
-619.6, -130.6 |
-375.1 (-2634.2, 1884.0) |
824.5 |
12.2 |
0.95 (0.92, 0.97) |
| Slow pace walking (min)a |
| ActiGraph wGT3X-BT |
169.1 (59.5) |
-25.4, 25.4 |
- |
- |
- |
- |
| Xiaomi Mi Band 2 |
40.1 (30.3) |
119.1, 139.0 |
129.1 (37.2, 221.0) |
129.1 |
77.7 |
0.11 (0.00, 0.36) |
| Xiaomi Mi Band 3 |
40.6 (31.5) |
118.4, 138.7 |
128.6 (35.1, 222.1) |
128.6 |
77.0 |
0.11 (0.00, 0.36) |
| Xiaomi Mi Band 4 |
45.1 (30.6) |
113.7, 134.4 |
124.0 (28.4, 219.6) |
124.0 |
74.4 |
0.11 (0.00, 0.35) |
| Xiaomi Mi Band 5 |
43.1 (30.1) |
116.4, 135.7 |
126.0 (36.4, 215.6) |
126.0 |
75.7 |
0.12 (0.00, 0.38) |
| Brisk pace walking (min)b |
| ActiGraph wGT3X-BT |
45.1 (28.4) |
-6.8, 6.8 |
- |
- |
- |
- |
| Xiaomi Mi Band 2 |
57.5 (34.7) |
12.1, 18.3 |
15.2 (-13.2, 43.6) |
17.6 |
50.1 |
0.78 (0.18, 0.92) |
| Xiaomi Mi Band 3 |
71.1 (47.6) |
14.1, 20.7 |
17.4 (-12.8, 47.6) |
19.9 |
54.9 |
0.74 (0.08, 0.90) |
| Xiaomi Mi Band 4 |
45.8 (29.0) |
11.7, 18.1 |
14.9 (-14.9, 44.7) |
17.7 |
50.1 |
0.78 (0.22, 0.91) |
| Xiaomi Mi Band 5 |
76.7 (34.9) |
10.5, 17.1 |
13.8 (-16.6, 44.2) |
17.5 |
51.6 |
0.78 (0.31, 0.91) |
| Slow-brisk pace walking (min)c |
| ActiGraph wGT3X-BT |
214.2 (71.1) |
-32.1, 32.1 |
- |
- |
- |
- |
| Xiaomi Mi Band 2 |
70.0 (46.1) |
134.2, 154.3 |
144.2 (51.1, 237.3) |
144.2 |
69.6 |
0.18 (0.00, 0.50) |
| Xiaomi Mi Band 3 |
68.3 (44.7) |
135.4, 156.5 |
145.9 (48.5, 243.3) |
145.9 |
69.8 |
0.16 (0.00, 0.48) |
| Xiaomi Mi Band 4 |
75.3 (47.2) |
128.4, 149.5 |
138.9 (41.3, 236.5) |
138.9 |
66.7 |
0.18 (0.00, 0.51) |
| Xiaomi Mi Band 5 |
74.4 (47.4) |
129.6, 150.1 |
139.8 (45.1, 234.5) |
139.8 |
67.2 |
0.19 (0.00, 0.52) |
| Moderate-to-vigorous physical activity (min) |
| ActiGraph GT3X+ |
45.1 (28.4) |
-6.8, 6.8 |
- |
- |
- |
- |
| Xiaomi Mi Band 2 |
29.9 (30.4) |
-21.2, -3.7 |
-12.4 (-93.2, 68.4) |
35.3 |
110.8 |
0.15 (0.00, 0.37) |
| Xiaomi Mi Band 3 |
27.7 (31.3) |
-37.3, -14.7 |
-26.0 (-130.5, 78.5) |
43.5 |
137.5 |
0.06 (0.00, 0.27) |
| Xiaomi Mi Band 4 |
30.1 (31.3) |
-8.6, 7.0 |
-0.8 (-72.9, 71.3) |
29.6 |
89.2 |
0.18 (0.00, 0.41) |
| Xiaomi Mi Band 5 |
31.3 (30.4) |
-40.8, -22.5 |
-31.6 (-116.1, 52.9) |
42.4 |
150.6 |
0.06 (0.00, 0.24) |
| Total physical activity (min) |
| ActiGraph wGT3X-BT |
214.2 (71.1) |
-32.1, 32.1 |
- |
- |
- |
- |
| Xiaomi Mi Band 2 |
86.9 (40.9) |
117.1, 137.5 |
127.3 (32.6, 222.0) |
127.3 |
60.1 |
0.19 (0.00, 0.52) |
| Xiaomi Mi Band 3 |
86.1 (41.6) |
117.6, 138.6 |
128.1 (31.1, 225.1) |
128.1 |
60.4 |
0.19 (0.00, 0.51) |
| Xiaomi Mi Band 4 |
89.8 (42.2) |
114.3, 134.6 |
124.4 (30.5, 218.3) |
124.4 |
58.7 |
0.20 (0.00, 0.54) |
| Xiaomi Mi Band 5 |
88.0 (41.3) |
115.8, 136.7 |
126.2 (29.8, 222.6) |
126.2 |
59.5 |
0.19 (0.00, 0.52) |
SD = Standard deviation; LOA = Limits of agreement; 90%/95% CI = 90%/95% confident interval; MAE = Mean absolute error; MAPE = Mean absolute percentage error; ICC = Intraclass correlation coefficient
a Compared with the accelerometer-measured light physical activity (min)
b Compared with the accelerometer-measured moderate-to-vigorous physical activity (min)
c Compared with the accelerometer-measured total physical activity (min).
