Table 1.

Clinical Laboratory Reference Instruments at 35 U.S. Medical Centers

Manufacturer (www.)	Reference instrument	Sites	Number of observations	Group	Bias (mg/dL) [SD, P], median (range)
Abbott (abbott.com)	Architect	1	30		− 1.47
	Areoset	1	25	55	[10.09, 0.284] 1 (− 43 to +17)
Bayer (bayer.com)	Advia 1650	2	51	51	− 3.82 [9.42, 0.006] − 3 (− 32 to + 18)
Beckman (beckman.com)	Beckman	3	90
	LX20	5	169
	LXI	1	37		− 2.72
	DCx	2	60	656	[11.57, <0.001]
	Synchron	2	70		− 1 (− 96 to + 45)
	LCX	1	200
	CX-9	1	30
Dade Behring (dadebehring.com)	RxL	4	270		− 0.64
	Dimension	1	30	384	[7.48, 0.09]
	Xpand	1	84		− 1 (− 29 to + 43)
Johnson & Johnson (jnjgateway.com)	Vitros Fusion	1	30
	Vitros	4	215		− 2.46
	Vitros 5.1	1	30	497	[8.86, <0.001]
	Vitros 250	1	72		− 2 (− 65 to + 16)
	Vitros 950	1	150
Olympus (olympusamerica.com)	AU series	1	30	30	− 7.03 [3.72, <0.001] −7 (−14 to 0)
Roche (rochediagnostics.com)	Integra	1	30	30	0.567 [9.37, 0.743] 5 (− 28 to + 9)
Types of instruments	20
Total medical centers		35
Total multicenter observations			1,703
Mean bias (mg/dL), all observations [SD, P]					− 2.2 [9.8, <0.001]
Median bias (mg/dL), all observations [range]					− 1 [− 96 to + 45]