Table 2. Mathematics for both BV and SM models.

Total Error
1. TE = |B| + 2I
Biological Variationa
2. $\text{TAE}=1.65(\mathrm{f}1\times \text{CVI})+\mathrm{f}2\sqrt{{(CVI)}^2+{(CVG)}^2}$
				CVI = 2.77% (NGSP 1.9%)
				CVG = 8.32% (NGSP 5.7%)
	Classification	f1	f2	TAE at HbA1c = 50 mmol/mol (6.7%)
				In Relative Units (%)		In Absolute Units (Concentration)
				IFCC	NGSP	IFCC mmol/mol	NGSP %
	Optimum	0.25	0.125	2.24	1.53	1.1	0.10
	Desirable	0.50	0.250	4.48	3.07	2.2	0.21
	Minimum	0.75	0.375	6.72	4.60	3.4	0.31
Sigma-metrics
3. $\sigma =\frac{(\text{TAE}-|\mathrm{B}|)}{\mathrm{I}}$
Conversion Factors NGSP from IFCC
4. HbA1c in Concentration Units:				NGSP = 0.0915IFCC + 2.15
5. Absolute Bias in Concentrations Units:				NGSP = 0.0915IFCC
6. Imprecision in CV% at 50 mmol/mol:				NGSP = 0.685IFCC
7. Imprecision in CV% in NGSP units:				IFCC = 1.46 NGSP
Symbols
TE	= Total Error			in concentration units
TAE	= Total Allowable Error			in concentration units
|B|	= Absolute Bias			in concentration units
I	= Imprecision			in concentration units
CVI	= Intra Individual Variation			in CV%
CVG	= Inter Individual Variation			in CV%
σ	= Chance Failure			in sigma units
f1	= Factor to classify the imprecision component of TAE
f2	= Factor to classify the bias component of TAE

^aCVI and CVG taken from the Ricos tables in NGSP units and converted to IFCC with equation 7