Table 2.
Reliability and clinical utility of the features derived from mobile and wearable sensors explored in this work
| Sensor | Feature | Daily average | Weekly average | EDSS | FSMC | PwMS vs HC | ||
|---|---|---|---|---|---|---|---|---|
| Coefficient | ICC | CI | ICC | CI | CORR | CORR | P value | |
| Physical | Max | 0.55 | [0.19 0.98] | 0.72 | [0.49 0.86] | −0.24* | −0.13 | <0.001 |
| Activity | Mean | 0.03 | [−0.06 0.82] | 0.80 | [0.62 0.9] | −0.35* | −0.32 | <0.001 |
| Min | 0.00 | [0.1 0.37] | 0.01 | [−0.37 0.37] | 0.18 | 0.22 | >0.01 | |
| Skew | 0.17 | [−0.01 0.92] | 0.85 | [0.71 0.93] | 0.07 | 0.03 | <0.001 | |
| Std | 0.02 | [−0.06 0.81] | 0.81 | [0.63 0.91] | −0.31 | −0.32 | <0.001 | |
| Steps | Max | 0.09 | [−0.02 0.87] | 0.24 | [−0.15 0.56] | −0.04 | −0.19 | <0.001 |
| Mean | 0.06 | [−0.04 0.85] | 0.83 | [0.67 0.92] | −0.41* | −0.28 | <0.01 | |
| Skew | 0.14 | [−0.01 0.91] | 0.46 | [0.11 0.71] | 0.40* | 0.20 | <0.001 | |
| Std | 0.18 | [−0. 0.92] | 0.84 | [0.69 0.92] | −0.44** | −0.30 | <0.001 | |
| Sum | 0.13 | [−0.01 0.9] | 0.84 | [0.68 0.92] | −0.40* | −0.28 | <0.01 | |
| Blood | Max | −0.02 | [−0.06 0.6] | 0.45 | [0.1 0.7] | −0.04 | 0.10 | <0.001 |
| Perfusion | Mean | 0.69 | [0.33 0.99] | 0.76 | [0.55 0.88] | 0.11 | 0.12 | >0.01 |
| (BP) | Min | 0.00 | [0.01, 0.92] | 0.00 | [0.05, 0.22] | −0.05 | 0.04 | >0.01 |
| Skew | 0.17 | [0. 0.91] | 0.57 | [0.27 0.78] | −0.02 | 0.01 | <0.01 | |
| Std | 0.26 | [0.05 0.94] | 0.67 | [0.4 0.83] | 0.15 | 0.28 | <0.001 | |
| Blood | Max | −0.02 | [−0.03 0.5] | 0.35 | [0.1 0.6] | −0.18 | −0.22 | >0.01 |
| Pulse | Mean | −0.03 | [−0.05 0.43] | 0.79 | [0.61 0.9] | 0.31 | 0.38* | <0.001 |
| Wave | Min | 0.00 | [0.02 0.64] | 0.02 | [−0.05 0.78] | −0.05 | 0.04 | >0.01 |
| (BPW) | Skew | 0.53 | [0.17 0.98] | 0.85 | [0.71 0.93] | −0.32 | −0.24 | <0.001 |
| Std | 0.15 | [0.01 0.9] | 0.77 | [0.56 0.89] | −0.23 | −0.05 | >0.01 | |
| Heart | Max | 0.26 | [0.03 0.95] | 0.66 | [0.39 0.83] | −0.41* | −0.48** | <0.001 |
| Rate | Mean | 0.23 | [0.03 0.93] | 0.79 | [0.61 0.9] | −0.01 | 0.09 | >0.01 |
| (HR) | Min | 0.58 | [0.23 0.98] | 0.69 | [0.45 0.85] | 0.33 | 0.44** | <0.001 |
| Skew | 0.44 | [0.12 0.97] | 0.37 | [0.01 0.65] | −0.00 | 0.07 | >0.01 | |
| std | 0.43 | [0.11 0.97] | 0.77 | [0.56 0.89] | −0.43** | −0.44** | <0.001 | |
| Heart | SD1 | 0.88 | [0.64 1.0] | 0.96 | [0.93 0.99] | −0.26 | −0.32 | <0.001 |
| Rate | SD2 | 0.91 | [0.71 1.0] | 0.96 | [0.93 0.99] | −0.38* | −0.47** | <0.001 |
| Variability | nn20 | 0.91 | [0.72 1.0] | 0.95 | [0.9 0.98] | −0.46** | −0.50** | <0.001 |
| (HRV) | nn50 | 0.91 | [0.74 1.0] | 0.96 | [0.93 0.98] | −0.36* | −0.41* | <0.001 |
| pnn20 | 0.71 | [0.36 0.99] | 0.95 | [0.9 0.98] | −0.44** | −0.48** | <0.001 | |
| pnn50 | 0.88 | [0.64 1.0] | 0.96 | [0.93 0.99] | −0.35* | −0.40** | <0.001 | |
| rmssd | 0.88 | [0.64 1.0] | 0.96 | [0.93 0.99] | −0.26 | −0.32 | <0.001 | |
| sdnn | 0.90 | [0.71 1.0] | 0.97 | [0.94 0.99] | −0.36* | −0.45** | <0.001 | |
| HF | 0.87 | [0.64 1.0] | 0.93 | [0.86 0.97] | −0.16 | −0.07 | <0.01 | |
| LF | 0.95 | [0.84 1.0] | 0.88 | [0.76 0.94] | −0.14 | −0.26 | <0.001 | |
| LF/HF | 0.23 | [0.03 0.94] | 0.95 | [0.91 0.98] | 0.29 | 0.26 | <0.001 | |
| Skin | Max | 0.45 | [0.14 0.97] | 0.28 | [−0.1 0.6] | 0.10 | 0.19 | <0.001 |
| Temperature | Mean | 0.02 | [−0.05 0.78] | 0.89 | [0.79 0.95] | 0.26 | 0.17 | <0.001 |
| (TEMP) | Min | 0.14 | [−0.01 0.9] | 0.96 | [0.92 0.98] | 0.12 | 0.10 | <0.001 |
| Skew | 0.65 | [0.28 0.99] | 0.74 | [0.52 0.87] | −0.05 | 0.07 | >0.01 | |
| Std | 0.12 | [−0.01 0.89] | 0.87 | [0.75 0.94] | −0.18 | −0.07 | <0.01 | |
| Phone | Locks | 0.89 | [0.68 1.0] | 0.93 | [0.86 0.97] | −0.36* | −0.49** | <0.001 |
| Unlocks | 0.91 | [0.73 1.0] | 0.91 | [0.73 1.0] | −0.35* | −0.46** | <0.001 | |
| Sleep | Hours | 0.10 | [0.01 0.84] | 0.64 | [0.32 0.82] | 0.09 | 0.06 | >0.01 |
| Tapping | Mean tapping frequency (tfm) | 0.06 | [−0.04 0.84] | 0.71 | [0.47 0.85] | −0.68** | −0.64** | >0.01 |
| task | Tapping count | 0.02 | [−0.05 0.79] | 0.71 | [0.47 0.86] | −0.65** | −0.62** | >0.01 |
| Δtfm | 0.02 | [−0.05 0.79] | 0.74 | [0.5 0.87] | −0.45** | −0.34* | >0.01 | |
ICC refers to the intraclass correlation coefficient, CI to the confidence interval, and CORR to Pearson or Spearman rank correlation. Reliable features with ICC more than or equal to 0.6 are marked in bold. * indicate p < 0.01, and ** values indicate p < 0.001 with Bonferroni correction. PwMS refers to PwMS and HC refers to healthy controls.