. 2019 May;40(2):79–97. doi: 10.33176/AACB-18-00017

Table 2.

Performance specifications of biomarkers NGAL and TIMP-2 calculated from previously reported analytical and biological variation data in urine.

	Literature values				Calculated values
	CV_I (%)	CV_G (%)	CV_A (%)	Ref.	Index of individuality (CV_I/CV_G)	TE_a (%)^*	RCV (%)^**
TIMP-2	67.7	119.7	6.0	150	0.57	90	188
NGAL	86.3	196.2	5.2	150	0.44	125	240

CV_I = within-subject variation, CV_G = between-subject variation, CV_A = analytical variation, TE_a = total allowable error, RCV = reference change value interval.

TE_a < k * 0.5 CV_I + 0.25(CV_I² + CV_G²)^1/2; With k = 1.65 (inner 90%, desired TE) and α = 0.05,

^**

RCV = z*2^1/2(CV_A² + CV_I²)^1/2, with z = 1.96 (95% probability that the change between results can be explained by biological and analytical variation only)