A5V4d

Sensitivity
Feverish illness in children
Table 8.4 Summary of results of meta-analysis of studies of PCT and CRP
170
PCT result (95% CI) CRP result (95% CI)
Number of studies 8 8
ROC area, AUROC 0.87 (0.84 to 0.90) 0.83 (0.79 to 0.86)
Sensitivity 0.80 (0.68 to 0.88) 0.80 (0.69 to 0.88)
Specificity 0.80 (0.71 to 0.87) 0.74 (0.68, 0.79)
Positive likelihood ratio 4.1 (2.9 to 5.7) 3.1 (2.5 to 3.7)
Negative likelihood ratio 0.25 (0.16 to 0.38) 0.27 (0.18 to 0.42)
Inconsistency (I-square) 96 (94 to 99) 92 (85 to 97)
AUROC area under the receiver operating characteristic curve, CI confidence interval, CRP C-reactive protein, PCT
procalcitonin, ROC receiver operating characteristic
The results of the meta-analysis are further summarised in Figure 8.2 shown below. The hierarchical
summary receiver operating characteristic (HSROC) is the summary ROC curve. Individual studies
are shown as circles, which are proportion to the study sample size. The 95% prediction region is
where the ROC curve could vary and the 95% confidence region is where the summary point estimate
could vary.
Figure 8.2 Predicted ROC curve with confidence intervals for PCT and CRP
1 − PCT 2 − CRP
.2 .4 .6 .8
1
0
1
.8
.6 .4
Specificity
Study estimate Summary point
HSROC curve
95% confidence
region
95% prediction
region
.2
Sensitivity
0
.2 .4 .6 .8
1
0
1
.8
.6 .4
Specificity
Study estimate Summary point
HSROC curve
95% confidence
region
95% prediction
region
.2
0
2013 Update