Procalcitonin as a Biomarker for a Bacterial Infection on Hospital Admission: A Critical Appraisal in a Cohort of Travellers with Fever after a Stay in (Sub)tropics

Table 2

(a) Descriptive statistics of procalcitonin (PCT) as an admission biomarker for a confirmed bacterial cause of fever in all 157 travellers. Data are given as proportion [95% confidence interval].

PCT test	Cutoff 0.5 ng /mL	Cutoff 2.0 ng/mL	Cutoff 10 ng/mL
Sensitivity	0.52[0.37-0.67]	0.20[0.10-0.34]	0.02[0.00-0.13]
Specificity	0.76[0.66-0.83]	0.91[0.84-0.95]	0.97[0.92-0.99]
Positive predictive value	0.47[0.33-0.61]	0.47[0.25-0.71]	0.25[0.01-0.78]
Negative predictive value	0.79[0.70-0.86]	0.73[0.65-0.80]	0.71[0.63-0.78]

(b) Descriptive statistics of procalcitonin (PCT) as an admission biomarker for a confirmed bacterial cause of fever in all 157 travellers if all patients with a likely infection (𝑛=88) were assumed to also have a confirmed bacterial infection. Data are given as proportion [95% confidence interval].

PCT test	Cutoff 0.5 ng /mL	Cutoff 2.0 ng /mL	Cutoff 10 ng /mL
Sensitivity	0.36[0.28-0.45]	0.13[0.08-0.20]	0.01[0.00-0.06]
Specificity	0.87[0.65-0.97]	0.91[0.70-0.98]	0.91[0.70-0.98]
Positive predictive value	0.94[0.83-0.98]	0.89[0.65-0.98]	0.50[0.09-0.91]
Negative predictive value	0.19[0.12-0.28]	0.15[0.10-0.23]	0.14[0.09-0.20]