The diagnostic values of PCT and CRP
As shown in Figure. 3 and Table. 3, for women at baseline and different times after their initial treatments (24, 48 and 72 hours), the areas under ROC curves of CRP were 0.588, 0.788 ,0.701, and 0.714, respectively, with statistically significant differences only in 24, 48 and 72 hours (p<0.001). As for PCT, the areas under ROC curves of the same time point were 0.763, 0.730, 0.901, and 0.902, respectively, with statistically significant differences in all the time points (p<0.001). Meanwhile, the areas of PCT were significantly better than those of CRP at baseline, 48 and 72 hours after the first injection (p<0.05).
Using the optimal cutoff value as the positive threshold, the sensitivities of CRP at baseline and different time after treatment (24, 48 and 72 hours) were 0.837, 0.918, 0.837, 0.786 and the specificities were 0.373, 0.542, 0.542, 0.644, respectively. As for PCT, the sensitivities at the same time were 0.765, 0.765, 0.796, and 0.816; the specificities were 0.746, 0.678, 0.932, and 0.949, respectively. Generally, CRP had high sensitivity but low specificity while PCT had high specificity and modest sensitivity. It is worth noting that both sensitivity and specificity of PCT were prominent initially at the baseline (cutoff, 0.031ng/ml), not to mention 48 hours (cutoff, 0.048 ng/ml) and 72 hours (cutoff, 0.051 ng/ml), which indicated PCT might be more sensitive for early diagnosis of HCA than CRP.
The positive predictive values (PPV) of PCT at the baseline and different times after initial treatment (24, 48, and 72 hours) were 0.819, 0.781, 0.946, and 0.960, all of which were better than the correspondingĀ negative predictive values (NPV) (0.679, 0.657, 0.753, and 0.775). In contrast, the PPV and NPV of CRP seemed to have no advantage in comparison with those of PCT at the same time; the PPV of PCT were especially prominent at 48 and 72 hours. These results demonstrated that PCT might be a reliable candidate for HCA diagnosis.