We also performed ROC analysis (Figure 1). We compared CRP and IMA ROC
curves for each Wagner classification. In addition, we estimated the
cut-off value, AUC, sensitivity, specificity, positive predictive value
(PPV) and negative predictive value (NPV) of CPR and IMA for each one
Wagner classification (Table 4). When we investigated the ROC curves for
Wagner grade 1 and 2, we found relative lower AUC, sensitivity and
specificity in terms of CRP and IMA. For Wagner grade 1 and 3, the AUC,
sensitivity and specificity values of CPR were higher than those of IMA.
When ROC curves of Wagner grade 1-4 and 1-5 classifications were
examined, it can be said that both CRP and IMA had relatively high AUC,
sensitivity and specificity values, but CPR values were higher than IMA.
Similar to the Wagner grade 1-3 comparison ROC curve, relatively low
AUC, sensitivity and specificity values were obtained in the Wagner
grade 2-3 ROC curve, in terms of CPR and IMA. We found relatively high
AUC, sensitivity and specificity values for both CRP and IMA in Wagner
grade 2-4 and 2-5 comparison ROC curves. In addition, for Wagner grade
3-4 and 3-5 comparison ROC curves, we found relatively high AUC,
sensitivity and specificity values for both CRP and IMA. Unlike other
Wagner grade ROC comparisons, the AUC, sensitivity and specificity
values of IMA for Wagner grade 4-5 were higher than those of CRP. When
the patient group was classified according to the presence of
osteomyelitis and the ROC curves were examined, it was observed that the
AUC, sensitivity and specificity values of CRP were higher than those of
IMA. We summarise all AUC, sensitivity, specificity, PPV and NPV data in
Table 4.
Table 4: Screening performance characteristics of CRP and IMA
in predicting Wagner classification.