Diagnostic utility of sepsis screening tools, procalcitonin, and C-reactive protein in nosocomial fever of unknown origin

Table 5 Diagnostic performance of serum procalcitonin and combined sepsis screening tools and procalcitonin

Parameters	PCT 0.85 μg/L	PCT 0.50 μg/L	qSOFA 2 + PCT 0.85 μg/L	SIRS 2 + PCT 0.85 μg/L
Sensitivity	77% (58-90)	77% (58-90)	72% (51-88)	76% (56-90)
Specificity	48% (28-69)	24% (9-45)	44% (22-69)	48% (28-69)
False negative rate	23% (10-42)	23% (10-42)	28% (12-49)	24% (10-44)
False positive rate	52% (31-72)	76% (55-91)	56% (31-78)	52% (31-72)
Positive likelihood ratio	1.47 (0.96-2.26)	1.01 (0.75-1.36)	1.30 (0.80-2.09)	1.46 (0.95-2.24)
Negative likelihood ratio	0.49 (0.23-1.05)	0.97 (0.38-2.52)	0.63 (0.28-1.42)	0.50 (0.23-1.08)
Diagnostic odds ratio	3.03 (0.96-9.62)	1.04 (0.30-3.69)	2.06 (0.57-7.36)	2.90 (0.91-9.23)
Youden’s index	0.25 (0.00-0.49)	0.01 (-0.22 to 0.23)	0.16 (-0.12 to 0.45)	0.24 (-0.01 to 0.49)

Values are given in percentage (95% confidence interval) or ratio (95% confidence interval). PCT: Procalcitonin; qSOFA: Quick Sequential Organ Failure Assessment; SIRS: Systemic inflammatory response syndrome.