Table 2 Descriptors of diagnostic accuracy of intracranial pressure measured with transcranial Doppler (ICPtcd) compared to invasive ICP measurement (ICPi) at three different ICP thresholds and three time frames (T1, T2 and T3)
ICP thresholds | Time frames of ICP measurements | Averaged values of all three time frames | ||
|---|---|---|---|---|
Above 20 mmHg | T1 | T2 | T3 | |
Optimal ICP threshold, mmHg | 16.5 (15.5–24.5) | 21.5 (16.5–27.0) | 21.5 (13.5–25.5) | 21.5 (12.5–24.5) |
Sensitivity, % | 75.8 (51.6–87.1) | 62.5 (42.5–80.0) | 65.9 (43.9–92.7) | 65.1 (44.2–90.7) |
Specificity, % | 66.0 (54.7–86.8) | 79.4 (65.8–90.5) | 78.4 (42.7–88.6) | 74.4 (40.2–88.1) |
PPV, % | 47.6 (40.0–63.0) | 38.4 (28.0–53.7) | 37.9 (25.4–51.6) | 32.6 (22.7–46.3) |
NPV, % | 87.4 (81.2–92.9) | 91.5 (88.1–95.0) | 90.9 (87.1–96.4) | 91.3 (88.2–95.7) |
1-NPV, % | 12.6 (7.1–18.8) | 8.5 (5.0–11.9) | 9.1 (3.6–12.9) | 8.7 (4.3–11.8) |
Accuracy, % | 69.7 (61.5–79.2) | 76.6 (66.5–84.5) | 75.2 (50.9–82.7) | 72.5 (48.5–82.1) |
LR + | 2.2 (1.1–6.6) | 3.0 (1.2–8.4) | 3.0 (0.8–8.2) | 2.5 (0.7–7.6) |
LR − | 0.4 (0.1–0.9) | 0.5 (0.2–0.9) | 0.4 (0.1–1.3) | 0.5 (0.1–1.4) |
AUC | 73.3 (65.7–80.8) | 69.0 (58.4–79.7) | 73.0 (64.6–81.4) | 71.5 (63.1–80.0) |
T1 | T2 | T3 | Average | |
|---|---|---|---|---|
Above 22 mmHg | ||||
Optimal ICP threshold mmHg | 16.5 (15.5–23.5) | 20.5 (16.5–25.5) | 21.5 (14.5–25.5) | 20.5 (15.5–29.5) |
Sensitivity, % | 86.8 (62.3–96.2) | 71.0 (48.4–87.1) | 75.0 (53.1–93.8) | 70.4 (40.7–92.6) |
Specificity, % | 66.1 (57.1–86.9) | 77.9 (62.0–89.9) | 75.8 (51.5–87.6) | 71.9 (51.9–94.0) |
PPV, % | 45.0 (38.9–62.7) | 32.7 (23.1–48.2) | 32.6 (22.7–47.2) | 23.0 (16.2–50.0) |
NPV, % | 93.6 (87.6–98.1) | 94.6 (91.9–97.6) | 94.8 (91.7–98.4) | 95.6 (93.1–98.5) |
1-NPV, % | 6.4 (1.9–12.4) | 5.4 (2.4–8.1) | 5.2 (1.6–8.3) | 4.4 (1.5–6.9) |
Accuracy, % | 71.5 (64.3–82.8) | 77.0 (64.4–86.2) | 75.2 (57.1–84.5) | 71.8 (55.3–89.7) |
LR + | 2.6 (1.5–7.3) | 3.2 (1.3–8.6) | 3.1 (1.1–7.6) | 2.5 (0.8–15.5) |
LR − | 0.4 (0.1–0.8) | 0.4 (0.1–0.8) | 0.3 (0.1–0.9) | 0.4 (0.1–1.1) |
AUC | 80.2 (73.8–86.7) | 74.1 (63.3–84.8) | 77.0 (68.4–85.6) | 75.6 (65.6–85.5) |
Above 25 mmHg | ||||
Optimal ICP threshold mmHg | 22.5 (18.5–24.5) | 19.5 (17.5–28.5) | 17.5 (14.5–29.5) | 25.5 (19.5–29.5) |
Sensitivity, % | 78.1 (59.4–90.6) | 81.0 (52.4–95.2) | 78.9 (47.4–100.0) | 81.2 (56.2–100.0) |
Specificity, % | 76.7 (63.0–86.8) | 72.5 (63.3–91.7) | 69.6 (46.4–91.3) | 84.1 (63.8–95.1) |
PPV, % | 35.5 (26.5–48.1) | 22.2 (16.3–42.9) | 18.6 (13.0–38.9) | 23.1 (13.1–48.3) |
NPV, % | 95.2 (92.0–98.0) | 97.3 (94.7–99.3) | 97.2 (94.5–100.0) | 98.6 (96.8–100.0) |
1-NPV, % | 4.8 (2.0–8.0) | 2.7 (0.7–5.3) | 2.8 (0.0–5.5) | 1.4 (0.0–3.2) |
Accuracy, % | 76.5 (65.6–84.6) | 73.2 (64.8–89.1) | 70.4 (50.0–88.5) | 83.6 (65.3–93.5) |
LR + (sens/1 − spec) | 3.4 (1.6–6.9) | 2.9 (1.4–11.5) | 2.6 (0.9–11.5) | 5.1 (1.6–20.5) |
LR − (1 − sens/spec) | 0.3 (0.1–0.6) | 0.3 (0.1–0.8) | 0.3 (0.0–1.1) | 0.2 (0.0–0.7) |
AUC | 78.4 (69.7–87.0) | 76.2 (64.2–88.2) | 75.1 (63.7–86.5) | 83.2 (71.4–94.9) |