Table 4 Performance characteristics of corrected slack angle and slack angle for classifying different severity of spasticity based on optimal cutoff values
Method | MAS ≥ 1+ (95% CI) | MAS ≥ 2 (95% CI) | MAS ≥ 3 (95% CI) |
|---|---|---|---|
Corrected slack angle | |||
Cutoff value | 3.75 | − 6.75 | − 10.25 |
AUROC | 0.906 (0.691–0.990) | 0.920 (0.709–0.993) | 0.987 (0.808–1.000) |
Sensitivity (%) | 93.75 (69.8–99.8) | 80.00 (44.4–97.5) | 100.00 (47.8–100.0) |
Specificity (%) | 75.00 (19.4–99.4) | 90.00 (55.5–99.7) | 93.33 (68.1–99.8) |
PPV (%) | 93.7 (68.6–99.9) | 88.9 (48.9–99.8) | 83.3 (31.1–99.8) |
NPV (%) | 75.0 (13.2–99.8) | 81.8 (46.3–98.1) | 100.0 (76.8–100.0) |
LR+ | 3.75 (2.1–6.7) | 8.00 (5.5–11.6) | 15.00 (13.1–17.2) |
LR− | 0.083 (0.007–1.1) | 0.22 (0.02–2.1) | 0 |
Slack angle | |||
Cutoff value | 0.25 | − 3.25 | − 6.75 |
AUC | 0.617 (0.377–0.822) | 0.605 (0.365–0.813) | 0.620 (0.379–0.824) |
Sensitivity (%) | 93.75 (69.8–99.8) | 80.00 (44.4–97.5) | 80.00 (28.4–99.5) |
Specificity (%) | 50.00 (6.8–93.2) | 50.00 (18.7–81.3) | 60.00 (32.3–83.7) |
PPV (%) | 88.2 (62.6–98.7) | 61.5 (31.6–86.1) | 2.00 (1.1–3.7) |
NPV (%) | 66.7 (4.0–99.8) | 71.4 (25.8–97.2) | 0.33 (0.05–2.1) |
LR+ | 1.87 (0.7–5.0) | 1.60 (0.8–3.2) | 40.0 (12.2–73.8) |
LR− | 0.13 (0.01–1.1) | 0.40 (0.1–1.6) | 90.0 (53.0–99.8) |