Table 2. Multiple linear regression models of clinical and environmental factors, which are independently associated with bias in blood glucose measurement with point-of-care glucometers.

Glucometer	Sampling site	Clinical and environmental factors	Measurement error (95%CI) §	P-value
Precision PCx	Arterial	Mean blood glucose (mg/dl) †	0.12 (0.08 to 0.16)	<0.001
		Hematocrit (%)	-0.89 (-1.38 to -0.40)	<0.001
Accu-chekAdvantage II	Arterial	Mean blood glucose (mg/dl) †	0.10 (0.06 to 0.15)	<0.001
		Hematocrit (%)	-0.74 (-1.29 to -0.19)	0.009
		Arterial pH	-34.8 (-62.8 to -6.7)	0.020
Accu-chekAdvantage II	Fingerstick	Mean blood glucose (mg/dl) †	0.12 (0.06 to 0.17)	<0.001
		Use of norepinephrine	-25.8 (-40.1 to -11.5)	0.001
		Hematocrit (%)	-1.04 (-1.75 to -0.32)	0.005
Accu-chekAdvantage II	Venous	Mean blood glucose (mg/dl) †	0.22 (0.13 to 0.30)	<0.001
		Arterial pH	-77.4 (-135.7 to -19.1)	0.010

^§ = Measurement error represents the change in the difference of blood glucose between point-of-care glucometer and arterial central lab measurement for one unit increase in the clinical or environmental factor;

^† = mean blood glucose is the mean between the point-of-care and arterial central lab blood glucose values; CI = confidence interval.