Diagnostic accuracy of cerebrospinal fluid protein markers for sporadic Creutzfeldt-Jakob disease in Canada: a 6-year prospective study

Table 3 Joint performance characteristics for tau, S100B and 14-3-3

Marker combination	Bivariate threshold^a	LR^{+ b, c}	95% CI	LR^{- b, d}	95% CI
Tau + S100B	T₉₇₆ + S_2.5 ^c	18.0	12.9-25.0	0.02	0.01-0.09
	T₃₀₀₀ + S_2.5	30.3	18.3-50.3	0.06	0.03-0.13
	T₅₀₀₀ + S_2.5	35.5	19.2-65.7	0.06	0.03-0.14
	T₁₀₀₀ + S_5.0	25.1	13.3-47.5	0.12	0.07-0.20
	T₃₀₀₀ + S_5.0	51.2	20.6-127.5	0.30	0.22-0.40
	T₅₀₀₀ + S_5.0	57.3	20.7-158.5	0.39	0.31-0.49
Tau + S100B + 14-3-3	T₉₇₆ + S_2.5 ^d	18.6	13.1-26.3	0.03	0.01-0.10
	T₃₀₀₀ + S_2.5	29.9	18.0-49.6	0.05	0.02-0.13
	T₅₀₀₀ + S_2.5	34.9	18.9-64.6	0.05	0.02-0.13
	T₁₀₀₀ + S_5.0	29.2	14.5-58.7	0.06	0.03-0.14
	T₃₀₀₀ + S_5.0	49.9	20.0-124.3	0.11	0.06-0.20
	T₅₀₀₀ + S_5.0	55.6	20.1-154.1	0.11	0.06-0.20

^a Bivariate thresholds are defined by combinations of individual thresholds in units of pg/mL (tau) and ng/mL (S100B), as indicated by subscripts.
^b LR⁺ and LR^- are positive and negative likelihood ratios, respectively. Values are estimates of joint diagnostic likelihood ratios for CSF tau, S100B and 14-3-3 proteins at illustrative bivariate cutoff thresholds.
^c To estimate joint LR⁺ and LR^- values for tau and S100B, the jointly positive patient subgroup was defined as having both tau and S100B results above the chosen pair of thresholds, and the jointly negative patient subgroup was defined as having both tau and S100B results below the chosen pair of thresholds.
^d To estimate joint LR⁺ and LR^- values for tau + S100B + 14-3-3, jointly positive and negative subgroups for tau and S100B were defined as in note c, and combined with positive and negative 14-3-3 assay results respectively.