Table 4.

Overview of the diagnostic parameters (with 95% confidence intervals) of joint fluid culture and multiplex PCR

Test	True positive	False positive	True negative	False negative	Sensitivity	Specificity	PPV	NPV	LR+	LR-
Joint fluid culture	10	1	10	5	0.67 (0.23, 0.63)	0.91 (0.59, 1.00)	0.91 (0.59, 1.00)	0.67 (0.38, 0.88)	7.33 (1.09, 49.16)	0.37 (0.17, 0.77)
Joint fluid multiplex PCR	12	0	11	3	0.8 (0.52, 0.96)	1.0 (0.69, 1.0)	1.0 (0.74, 1.0)	0.77 (0.46, 0.95)	n/a	0.2 (0.07, 0.55)

PPV positive predictive value; NPV negative predictive value; LR+ positive likelihood ratio; LR- negative likelihood ratio