Table 2.

Quantitative agreement between the Kehua assay and the two imported reference systems, including Pearson correlation, Spearman correlation, Lin’s concordance correlation coefficient and Passing-Bablok regression.

Comparison	Analyte	n	Pearson r	Spearman r	Lin’s CCC	PB slope	PB intercept
Kehua vs Freelite	FLC-κ	133	0.988	0.974	0.986	0.989	0.223
Kehua vs Freelite	FLC-λ	133	1.000	0.951	0.999	1.077	−0.787
Kehua vs Freelite	κ/λ ratio	133	0.999	0.825	0.983	1.022	0.018
Kehua vs N Latex	FLC-κ	122	0.991	0.978	0.984	0.870	1.063
Kehua vs N Latex	FLC-λ	122	0.995	0.953	0.569	1.138	0.230
Kehua vs N Latex	κ/λ ratio	122	0.998	0.834	0.922	0.733	0.123

CCC, concordance correlation coefficient; PB, Passing-Bablok regression. All P-values for Pearson correlation < 0.001. The reduced CCC for Kehua vs N Latex FLC-λ reflects the influence of a single extreme outlier with FLC-λ > 9–000 mg/L; Pearson correlation, which is on a different scale, remained excellent.