Table 3.

Diagnostic sensitivity and specificity of the FLC indices compared to OCB.

	OCB	KFLC	p-value	LFLC	p-value
CIS/MS vs controls
Sensitivity	0.82 (95% CI = 0.79–0.85)	0.88 (95% CI = 0.85–0.90)	< 0.001	0.66 (95% CI = 0.62–0.70)	< 0.001
Specificity	0.92 (95% CI = 0.89–0.96)	0.83 (95% CI = 0.78–0.88)	< 0.001	0.86 (95% CI = 0.81–0.91)	0.019
Accuracy	0.85 (95% CI = 0.82–0.88)	0.86 (95% CI = 0.84–0.89)	1.000	0.74 (95% CI = 0.70–0.77)	< 0.001
PPV	0.96 (95% CI = 0.94–0.98)	0.92 (95% CI = 0.90–0.95)	< 0.001	0.92 (95% CI = 0.90–0.95)	0.001
NPV	0.68 (95% CI = 0.63–0.73)	0.73 (95% CI = 0.68–0.79)	0.010	0.53 (95% CI = 0.48–0.58)	< 0.001
CIS vs controls
Sensitivity	0.77 (95% CI = 0.72–0.82)	0.81 (95% CI = 0.76–0.86)	0.150	0.60 (95% CI = 0.54–0.66)	< 0.001
Specificity	0.92 (95% CI = 0.89–0.96)	0.83 (95% CI = 0.78–0.88)	< 0.001	0.86 (95% CI = 0.82–0.91)	0.019
Accuracy	0.84 (95% CI = 0.80–0.88)	0.82 (95% CI = 0.78–0.85)	0.149	0.73 (95% CI = 0.68–0.77)	< 0.001
PPV	0.92 (95% CI = 0.88–0.95)	0.84 (95% CI = 0.79–0.88)	< 0.001	0.83 (95% CI = 0.77–0.89)	0.001
NPV	0.78 (95% CI = 0.73–0.83)	0.79 (95% CI = 0.74–0.84)	0.56	0.66 (95% CI = 0.61–0.72)	< 0.001
MS vs controls
Sensitivity	0.86 (95% CI = 0.82–0.90)	0.93 (95% CI = 0.90–0.97)	< 0.001	0.75 (95% CI = 0.70–0.80)	< 0.001
Specificity	0.92 (95% CI = 0.89–0.96)	0.83 (95% CI = 0.78–0.88)	< 0.001	0.86 (95% CI = 0.81–0.91)	0.019
Accuracy	0.89 (95% CI = 0.86–0.92)	0.89 (95% CI = 0.86–0.92)	1.000	0.80 (95% CI = 0.77–0.84)	< 0.001
PPV	0.94 (95% CI = 0.91–0.97)	0.88 (95% CI = 0.84–0.91)	< 0.001	0.88 (95% CI = 0.84–0.92)	0.002
NPV	0.84 (95% CI = 0.79–0.88)	0.91 (95% CI = 0.86–0.95)	0.001	0.73 (95% CI = 0.68–0.78)	< 0.001

FLC: free light chains; OCB: oligoclonal IgG bands; KFLC: kappa free light chains; LFLC: lambda free light chains; CIS: clinically isolated syndrome; MS: multiple sclerosis; PPV: positive predictive value; NPV: negative predictive value.

To compare the sensitivity and specificity between the two different diagnostic tools (OCB and FLC), the McNemar test was used.