Correlation between individual biomarkers and pathology-proved spondylodiscitisa
| Positive Pathologyy | ||||||
|---|---|---|---|---|---|---|
| r | P | PPV | NPV | Sensitivity | Specificity | |
| Epidural enhancement | ||||||
| Observer 1 | 0.52 | <.001c | 61.3 | 87.8 | 79.2 | 75.0 |
| Observer 2 | 0.36 | .002c | 42.1 | 100 | 100 | 31.3 |
| Observer 3 | 0.33 | .004c | 40.7 | 100 | 100 | 27.1 |
| Majority consensus | 0.41 | .001c | 44.4 | 100 | 100 | 37.5 |
| Paraspinal enhancement | ||||||
| Observer 1 | 0.27 | .02c | 40.7 | 88.9 | 91.7 | 33.3 |
| Observer 2 | 0.23 | .05c | 36.9 | 100 | 100 | 14.6 |
| Observer 3 | 0.24 | .04c | 43.6 | 78.8 | 70.8 | 54.2 |
| Majority consensus | 0.33 | .01c | 40.7 | 100 | 100 | 27.1 |
| Hyperintense T2 disc signal | ||||||
| Observer 1 | 0.37 | .02c | 55.5 | 80.1 | 86.5 | 45.0 |
| Observer 2 | 0.19 | .03c | 33.0 | 100 | 100 | 20.2 |
| Observer 3 | 0.21 | .03c | 41.2 | 79.2 | 73.1 | 51.0 |
| Majority consensus | 0.29 | .03c | 51.0 | 100 | 100 | 33.2 |
| Vertebral endplate erosion | ||||||
| Observer 1 | 0.333 | .01c | 46.0 | 83.4 | 88.8 | 30.2 |
| Observer 2 | 0.22 | .05c | 35.6 | 95.5 | 93.2 | 25.7 |
| Observer 3 | 0.30 | .0c | 39.4 | 80.6 | 75.6 | 56.7 |
| Majority consensus | 0.31 | .02c | 42.1 | 92.3 | 92.0 | 35.6 |
| Blood culture growth | 0.06 | .63 | 50 | 66.7 | 4.2 | 97.9 |
| Fever status | 0.26 | .03c | 48.3 | 76.7 | 58.3 | 68.8 |
| Leukocytosis | 0.032 | .80 | 40 | 64.3 | 16.7 | 85.7 |
| Hemoglobin countb | –0.05 | .67 | NA | NA | NA | NA |
| Platelet countb | 0.20 | .11 | NA | NA | NA | NA |
| ALP levelb | –0.03 | .84 | NA | NA | NA | NA |
| ESRb | –0.09 | .49 | NA | NA | NA | NA |
| CRPb | 0.29 | .02c | NA | NA | NA | NA |
Note:—NA indicates not applicable; ALP, alkaline phosphatase.
↵a The Spearman correlation was used for rank/categoric variables. PPV, NPV, sensitivity, and specificity numbers are represented in percentages. Continuous variables will not have PPV, NPV, sensitivity, or specificity values without established thresholds.
↵b Continuous variables in which the Pearson correlation was used.
↵c Statistically significant P values (<.05).