Detection of Echinococcus multilocularis by MC-PCR: evaluation of diagnostic sensitivity and specificity without gold standard

Figures & data

Table 1 Results of the analysis with SCT and MC-PCR on data set A (n=108) and data set B (n=69)

	SCT+	SCT−	Total
Data set A
MC-PCR+	50	7	57
MC-PCR−	5	46	51
Total	55	53	108
Data set B
MC-PCR+	32	11	43
MC-PCR−	6	20	26
Total	38	31	69

Table 2 Distributions for prior information of known variables (Se=sensitivity, Sp=specificity)

Parameter	Most likely value (mode)	Percentile	Percentile's value	Beta distribution	Reference
SpSCT	0.9999	1	0.99	Beta(5836, 1.584)	(15)
SeSCT	0.8360	10	0.76	Beta(45.24, 9.68)	(10, (16))
SpMC-PCR	0.9900	5	0.95	Beta(88.28, 1.882)	(6)

Table 3 Posterior median and 95% posterior credible intervals (PCI) of the sensitivity (Se) and specificity (Sp) of the MC-PCR and SCT

Parameter	Estimate	95% PCI	Null hypothesis (H0)	POPR
SeMC-PCR	0.88	[0.80; 0.93]	SeSCT>SeMC-PCR	0.14
SeSCT	0.83	[0.76; 0.88]
SpMC-PCR	0.98	[0.94; 0.99]	SpSCT<SpMC-PCR	<0.001
SpSCT	0.99	[0.99; 1]

POPR, Bayesian posterior probabilities; PCI, posterior credible intervals.

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