Table 2.
ICC (95% CI), Mean Percent Error (95% CI), and Absolute Percent Error (95% CI) by Ambulatory Category
| ICC | MPE | MAPE | |
|---|---|---|---|
| Nonimpaired (N = 25) | |||
| StepWatch | 0.87 (0.68, 0.95) | −4.42 (−0.41, −8.43) | 5.25 (1.45, 9.05) |
| Fitbit One | 0.80 (0.60, 0.91) | −2.59 (0.04, −5.23) | 2.69 (0.07, 5.31) |
| Omron | 0.72 (0.42, 0.87) | −4.48 (−1.20, −7.76) | 4.47 (1.19, 7.76) |
| Fitbit Flex | 0.15 (−0.12, 0.45) | −26.94 (−14.26, −39.61) | 27.65 (15.27, 40.03) |
| Jawbone UP | 0.55 (0.21, 0.78) | −2.86 (4.32, −10.04) | 10.87 (5.20, 16.53) |
| Impaired (N = 25) | |||
| StepWatch | 0.91 (0.74, 0.97) | −3.45 (0.06, −6.96) | 3.76 (0.34, 7.18) |
| Fitbit One | 0.96 (0.88, 0.99) | −1.71 (−0.69, −2.73) | 1.81 (0.82, 2.79) |
| Omron | 0.89 (0.63, 0.96) | −3.15 (−1.37, −4.93) | 3.21 (1.45, 4.96) |
| Fitbit Flex | 0.25 (−0.10, 0.69) | −16.31 (−10.90, −21.71) | 16.30 (10.90, 21,70) |
| Jawbone UP | 0.50 (0.10, 0.75) | −8.43 (−2.93, −13.92) | 9.50 (4.34, 14.66) |
| Cane-user (N = 25) | |||
| StepWatch | 0.98 (0.95, 0.99) | −1.78 (0.06, −3.61) | 2.29 (0.57, 4.01) |
| Fitbit One | −0.16 (−0.19, 0.50) | −11.48 (−1.84, −21.11) | 11.47 (1.84, 21.11) |
| Omron | −0.61 (−0.37, 0.32) | −17.64 (−3.23, −32.06) | 18.56 (4.37, 32.75) |
| Fitbit Flex | 0.05 (−0.27, 0.41) | −22.88 (−4.57, −41.19) | 35.89 (21.77, 50.01) |
| Jawbone UP | −0.04 (−0.31, 0.29) | −34.10 (−13.44, −54.75) | 46.03 (29.77, 62.29) |
| Walker-user (N = 24) | |||
| StepWatch | 0.99 (0.98, 0.99) | −1.33 (0.57, −3.22) | 1.75 (−0.05, 3.56) |
| Fitbit One | −0.38 (−0.58, 0.13) | −23.25 (−8.99, −37.51) | 23.25 (8.99, 37.51) |
| Omron | −0.16 (−0.37, 0.19) | −33.72 (−17.84, −49.61) | 33.72 (17.83, 49.61) |
| Fitbit Flex | −0.03 (−0.13, 0.16) | −57.40 (−44.36, −70.43) | 57.39 (44.35, 70.43) |
| Jawbone UP | −0.01 (−0.05, 0.07) | −94.27 (−83.71, −104.84) | 95.36 (87.04, 103.67) |
Notes: CI = confidence interval; ICC = intraclass correlation coefficients; MAPE = mean absolute percent error; MPE = mean percent error.