Table 4.
Descriptive statistics of step count by activity tracker compared to the gold standard.
| Activity tracker | Number of participants | Average mean difference in step count (SD)a | Average median difference in step count (25 to 75 percentile)a | Limits of agreement (lower bound–upper bound) |
| Accupedo | 50 | –176.3 (132.1) | –174.5 (–251.0 to –102.5) | –435.2 to 82.7 |
| Activ8 | 62 | 107.3 (251.9) | 126.0 (30.5 to 243.5) | –471.3 to 721.0 |
| Digi-Walker CW-700 | 52 | –284.5 (129.0) | –253.0 (–383.0 to –169.0) | –537.4 to –31.7 |
| Fitbit Flex | 47 | –93.5 (126.7) | –111.0 (–167.0 to 3.0) | –326.9 to 123.7 |
| Lumoback | 51 | –178.5 (96.0) | –168.0 (–205.5 to –117,0) | –366.9 to 9.3 |
| Moves | 48 | –146.6 (216.3) | –215.0 (–279.5 to –89.3) | –570.5 to 277.4 |
| Fitbit One | 49 | –29.7 (155.1) | –8.0 (–160.0 to 128.0) | –367.8 to 308.6 |
| UP24 | 49 | –252.4 (104.7) | –266.0 (–327.0 to –176.5) | –457.7 to –47.2 |
| Walking Style X | 50 | –204.4 (117.7) | –206.5 (–256.0 to –105.0) | –438.0 to 27.2 |
aActivity tracker minus gold standard.