TABLE 3.
Sensitivity and specificity of the combined calls from the 6 observers on 40 lesions with histologic diagnoses (n = 240 calls)
| (a) Intradural/extramedullary lesions | ||
|---|---|---|
| Test result | ||
| IDEM diagnosed | IDEM not diagnosed | |
| Histological IDEM | 67 | 41 |
| Non‐IDEM | 5 | 127 |
| Value | 95% CI | |
|---|---|---|
| Sensitivity | 62.0% | 52.2–71.2 |
| Specificity | 96.2% | 91.4‐98.8 |
| Positive likelihood ratio | 16.4 | 6.9‐39.2 |
| Negative likelihood ratio | 0.39 | 0.31‐0.50 |
| Disease prevalence | 45.0% | 38.6‐51.5 |
| Positive predictive value a | 93.1% | 84.8‐97.0 |
| Negative predictive value a | 75.6% | 70.8‐79.8 |
| Accuracy a | 80.8% | 75.3‐85.6 |
| (b) Intramedullary lesions | ||
|---|---|---|
| Test result | ||
| IM diagnosed | IM not diagnosed | |
| Histological IM | 35 | 7 |
| Non‐IM | 42 | 156 |
| Value | 95% CI | |
|---|---|---|
| Sensitivity | 83.3% | 68.6‐93.0 |
| Specificity | 78.8% | 72.4‐84.3 |
| Positive likelihood ratio | 3.93 | 2.9‐5.31 |
| Negative likelihood ratio | 0.21 | 0.11‐0.42 |
| Disease prevalence | 17.5% | 12.9‐22.9 |
| Positive predictive value a | 45.5% | 38.2‐53.0 |
| Negative predictive value a | 95.7% | 91.9‐97.8 |
| Accuracy a | 79.6% | 73.9‐84.5 |
| (c) Degenerative myelopathy | ||
|---|---|---|
| Test result | ||
| DM diagnosed | DM not diagnosed | |
| Histological DM | 78 | 12 |
| Non‐DM | 13 | 137 |
| Value | 95% CI | |
|---|---|---|
| Sensitivity | 86.7% | 77.9‐92.9 |
| Specificity | 91.3% | 85.6‐95.3 |
| Positive likelihood ratio | 10.00 | 5.91‐16.92 |
| Negative likelihood ratio | 0.15 | 0.09‐0.25 |
| Disease prevalence | 37.5% | 31.3‐44.0 |
| Positive predictive value a | 85.7% | 78.0‐91.0 |
| Negative predictive value a | 92.0% | 87.1‐95.1 |
| Accuracy a | 89.6% | 85.0‐93.1 |
Abbreviations: DM, degenerative myelopathy; IDEM, intradural‐extramedullary; IM, intramedullary.
a
Indicates the value is dependent upon disease prevalence in a study population.