Table 4.
Initial contact detection (ICD) performance measures. Sensitivity, positive predictive value, absolute and relative errors, and overall performance index for the ICD algorithms. Values are expressed as mean and 95% confidence intervals (CI) for each cohort. In italic face: recommended algorithms. Underlined performance index indicates top-ranked algorithm for the specific cohort of that row
| Cohort | Initial contact detection | ||||
|---|---|---|---|---|---|
| Sensitivity | Positive predictive value | Absolute error [s] | Relative error [%] | Performance index | |
| ICDA | |||||
| HA | 0.80 [0.79, 0.81] | 0.91 [0.90, 0.92] | 0.06 [0.05, 0.06] | 8.0 [7.7, 8.3] | 0.804 |
| CHF | 0.79 [0.77, 0.80] | 0.89 [0.88, 0.91] | 0.07 [0.06, 0.07] | 10.9 [10.1, 11.8] | 0.771 |
| COPD | 0.81 [0.81, 0.82] | 0.93 [0.92, 0.94] | 0.07 [0.06, 0.07] | 9.1 [8.8, 9.3] | 0.790 |
| MS | 0.80 [0.79, 0.82] | 0.92 [0.91, 0.93] | 0.06 [0.06, 0.06] | 8.4 [8.1, 8.7] | 0.805 |
| PD | 0.79 [0.77, 0.80] | 0.90 [0.89, 0.91] | 0.06 [0.06, 0.06] | 8.3 [7.9, 8.6] | 0.798 |
| PFF | 0.80 [0.78, 0.81] | 0.89 [0.88, 0.90] | 0.05 [0.05, 0.06] | 7.6 [7.3, 7.9] | 0.818 |
| ICDB | |||||
| HA | 0.80 [0.79, 0.81] | 0.86 [0.85, 0.87] | 0.13 [0.13, 0.13] | 18.0 [17.8, 18.3] | 0.641 |
| CHF | 0.80 [0.78, 0.81] | 0.88 [0.86, 0.90] | 0.13 [0.13, 0.14] | 19.9 [19.3, 20.4] | 0.641 |
| COPD | 0.78 [0.77, 0.79] | 0.85 [0.84, 0.86] | 0.15 [0.15, 0.15] | 21.2 [20.9, 21.5] | 0.590 |
| MS | 0.75 [0.73, 0.77] | 0.81 [0.79, 0.83] | 0.14 [0.14, 0.15] | 19.8 [19.3, 20.4] | 0.595 |
| PD | 0.80 [0.78, 0.81] | 0.86 [0.84, 0.88] | 0.14 [0.14, 0.14] | 19.2 [18.9, 19.6] | 0.620 |
| PFF | 0.80 [0.79, 0.82] | 0.86 [0.85, 0.88] | 0.13 [0.13, 0.13] | 17.9 [17.5, 18.2] | 0.641 |
| ICDC | |||||
| HA | 0.82 [0.81, 0.83] | 0.86 [0.85, 0.88] | 0.06 [0.06, 0.07] | 8.9 [8.6, 9.2] | 0.795 |
| CHF | 0.81 [0.80, 0.82] | 0.87 [0.85, 0.88] | 0.07 [0.07, 0.08] | 11.1 [10.2, 11.9] | 0.771 |
| COPD | 0.83 [0.82, 0.83] | 0.90 [0.89, 0.91] | 0.07 [0.07, 0.07] | 9.7 [9.4, 9.9] | 0.786 |
| MS | 0.82 [0.81, 0.84] | 0.89 [0.87, 0.90] | 0.07 [0.06, 0.07] | 9.2 [8.8, 9.6] | 0.783 |
| PD | 0.80 [0.78, 0.81] | 0.84 [0.82, 0.86] | 0.07 [0.07, 0.07] | 9.4 [9.0, 9.8] | 0.766 |
| PFF | 0.80 [0.79, 0.82] | 0.81 [0.79, 0.82] | 0.07 [0.07, 0.07] | 9.6 [9.2, 10.0] | 0.759 |
| ICDD | |||||
| HA | 0.78 [0.77, 0.79] | 0.88 [0.87, 0.89] | 0.10 [0.10, 0.10] | 14.1 [13.8, 14.5] | 0.705 |
| CHF | 0.79 [0.78, 0.81] | 0.92 [0.91, 0.93] | 0.09 [0.09, 0.10] | 13.8 [13.4, 14.3] | 0.735 |
| COPD | 0.76 [0.75, 0.77] | 0.89 [0.88, 0.90] | 0.11 [0.11, 0.12] | 15.9 [15.5, 16.3] | 0.680 |
| MS | 0.78 [0.77, 0.80] | 0.89 [0.88, 0.91] | 0.10 [0.10, 0.11] | 14.4 [13.9, 15.0] | 0.706 |
| PD | 0.76 [0.75, 0.78] | 0.86 [0.84, 0.87] | 0.11 [0.11, 0.11] | 15.4 [15.0, 15.8] | 0.674 |
| PFF | 0.80 [0.78, 0.81] | 0.86 [0.85, 0.88] | 0.10 [0.09, 0.10] | 13.6 [13.1, 14.1] | 0.706 |
HA healthy adults; PD Parkinson’s disease; MS multiple sclerosis; COPD chronic obstructive pulmonary disease; CHF congestive heart failure; PFF proximal femoral fracture; LoA limits of agreement