Table 6.
Predictive values for the postoperative neurological outcome for the left TA and right TA separately.
| Tibialis Anterior Left * | ||||
|---|---|---|---|---|
| Predictive values of mTc-MEP warnings for new postoperative motor deficits % (CI) | ||||
| Without RW (n = 195) | RW as TP (n = 204) | RW as FP (n = 204) | RW after application of causality guidelines (n = 204) *** | |
| Sensitivity | 100.0 (47.8–100.0) | 100.0 (76.8–100.0) | 100 (47.8–100.0) | 100 (59.0–100.0) |
| Specificity | 97.4 (94.0–99.1) | 97.37 (94.0–99.1) | 93.0 (88.5–96.1) | 93.9 (89.6–96.8) |
| Positive predictive value | 50.0 (29.6–70.4) | 73.7 (54.1–86.9) | 26.3 (17.7–37.2) | 36.8 (25.2–50.2) |
| Negative predictive value | 100.0 (100.0–100.0) | 100.0 (100.0–100.0) | 100.0 (100.0–100.0) | 100.0 (100.0–100.0) |
| Tibialis Anterior Right ** | ||||
| Predictive values of mTc-MEP warnings for new postoperative motor deficits % (CI) | ||||
| Without RW (n = 197) | RW as TP (n = 206) | RW as FP (n = 206) | RW after application of causality guidelines (n = 206) *** | |
| Sensitivity | 87.5 (47.4–99.7) | 94.1 (71.3–99.9) | 87.5 (47.4–99.7) | 92.3 (64.0–99.8) |
| Specificity | 97.9 (94.7–99.4) | 97.9 (94.7–99.4) | 93.4 (89.0–96.5) | 95.9 (92.0–98.2) |
| Positive predictive value | 63.6 (39.1–82.7) | 80.0 (60.1–91.4) | 35.0 (23.0–49.2) | 60.0 (42.8–75.1) |
| Negative predictive value | 99.5 (96.7–99.9) | 99.5 (96.5–99.2) | 99.5 (88.9–96.2) | 99.5 (91.9–98.0) |
* In four patients, the tibialis anterior left was not elicitable. In one patient there was a warning, however no preoperative neurological examination was performed. In one patient, there was no postoperative neurological examination. These six patients were excluded from this table. ** In two patients, the tibialis anterior left was not elicitable. In one patient there was a warning; however, no preoperative neurological examination was performed. In one patient, there was no postoperative neurological examination. These four patients were excluded from this table. *** For the left TA, two out of the nine patients with a reversible warning were considered true positive. For the right TA, five out of the nine patients with a reversible warning were considered true positive. RW, reversible warnings; TP, true positives; FP, false positives.