Table 2.
Concurrent validity of the Health app with the APDM Mobility Lab.
| Parameter | Apple Health app | APDM Mobility Lab | Bias (95% CI) | 95% LOA | PE | ICC2,1 (95% CI) |
|---|---|---|---|---|---|---|
| Gait speed (m/s) | ||||||
| Children (n = 24) | 1.36 ± 0.16 | 1.34 ± 0.18 | 0.02 (− 0.01 to 0.06) | − 0.15 to 0.20 | 13.0 | 0.86 (0.70–0.94) |
| Adults (n = 27) | 1.36 ± 0.17 | 1.32 ± 0.16 | 0.04 (0.00 to 0.07) | − 0.12 to 0.19 | 11.6 | 0.86 (0.70–0.94) |
| Seniors (n = 29) | 1.28 ± 0.19 | 1.23 ± 0.19 | 0.06 (0.02 to 0.09) | − 0.12 to 0.23 | 14.1 | 0.85 (0.61–0.94) |
| Step length (cm) | ||||||
| Children (n = 24) | 68.9 ± 4.7 | 67.1 ± 6.0 | 1.8 (− 0.4 to 4.0) | − 8.3 to 11.8 | 14.8 | 0.53 (0.18–0.76) |
| Adults (n = 27) | 71.8 ± 6.8 | 69.0 ± 6.2 | 2.9 (1.5 to 4.3) | − 4.0 to 9.7 | 9.8 | 0.78 (0.34–0.92) |
| Seniors (n = 29) | 66.6 ± 7.4 | 63.2 ± 7.5 | 3.4 (1.7 to 5.1) | –5.1 to11.9 | 13.1 | 0.76 (0.32–0.90) |
| Double support time (%) | ||||||
| Children (n = 18) | 25.4 ± 2.3 | 25.5 ± 4.7 | − 0.1 (− 1.9 to 1.7) | − 7.1 to 7.0 | 27.7 | 0.54 (0.09–0.80) |
| Adults (n = 24) | 27.1 ± 1.8 | 27.9 ± 3.6 | − 0.8 (− 1.8 to 0.3) | − 5.8 to 4.3 | 18.4 | 0.58 (0.25–0.79) |
| Seniors (n = 24) | 27.6 ± 2.0 | 28.3 ± 5.5 | − 0.6 (− 2.5 to 1.3) | − 9.5 to 8.2 | 31.6 | 0.42 (0.02–0.70) |
Descriptive data given as mean ± standard deviation.
CI confidence interval, LOA limits of agreement, PE percentage error, ICC intraclass correlation coefficient.