Table 2.
The performance of variable combinations in predicting positive microbiology from a biopsy. (TP = true positive, TN = true negative, FP = false positive, FN = false negative)
| Sensitivity TP/(TP + FN) |
Specificity TN/(TN + FP) |
PPV TP/(TP + FP) |
NPV TN/(TN + FN) | |
|---|---|---|---|---|
| Paravertebral abscess and non-sclerotic erosion | 4/11 = 36.4% (10.9%–69.2%) |
29/29 = 100.0% (88.1%–100.0%) |
4/4 = 100.0%
(39.8%–100.0%) |
29/36 = 80.6% (64.0%–91.8%) |
| Paravertebral abscess or non-sclerotic erosion | 9/11 = 81.8% (48.2%–97.7%) |
21/29 = 72.4% (52.8%–87.3%) |
9/17 = 52.9% (27.8%–77.0%) |
21/23 = 91.3% (72.0%–98.9%) |
| Paravertebral abscess and CRP > 50 | 6/11 = 54.6% (23.4%–83.3%) |
28/29 = 96.6% (82.2%–99.9%) |
6/7 = 85.7%
(42.1%–99.6%) |
28/33 = 84.8% (68.1%–94.9%) |
| Paravertebral abscess or CRP > 50 | 8/11 = 72.7% (39.0%–94.0%) |
16/29 = 55.2% (35.7%–73.6%) |
8/19 = 38.1% (18.1%–61.6%) |
16/21 = 84.2% (60.4%–96.6%) |
| CRP > 50 and non-sclerotic erosion | 3/11 = 27.3% (6.0%–61.0%) |
28/29 = 96.6% (82.2%–99.9%) |
3/4 = 75.0%
(19.4%–99.4%) |
28/36 = 77.8% (60.9%–89.9%) |
| CRP > 50 or non-sclerotic erosion | 10/11 = 90.9% (58.7%–99.8%) |
22/29 = 75.9% (56.5%–89.7%) |
10/17 = 58.8% (32.9%–81.6%) |
22/23 = 95.7% (78.1%–99.9%) |
| Paravertebral abscess and non-sclerotic erosion and CRP > 50 | 3/11 = 27.3% (6.0%–61.0%) |
29/29 = 100.0% (88.1%–100.0%) |
3/3 = 100.0%
(29.2%–100.0%) |
29/37 = 78.4% (61.8%–90.2%) |
| Paravertebral abscess or non-sclerotic erosion or CRP > 50 | 10/11 = 90.9% (58.7%–99.8%) |
16/29 = 55.2% (35.7%–73.6%) |
10/23 = 43.5% (23.2%–65.5%) |
16/17 = 94.1%
(71.3%–99.9%) |