TABLE 3.

Variance partition coefficients for algorithm-, vendor, site-, and participant-level effects for the metabolite levels (shown as percentage). The residual represents the part of the total variance which is not explained by the linear mixed-effect model. Asterisks indicate significant effects based on linear mixed-effect modeling (p < 0.05 = * and p < 0.01 = **)

	[tNAA] / [tCr]	[tCho] / [tCr]	[mI] / [tCr]	[Glx] / [tCr]
Algorithm	3.2%**	0.7%*	58.7%*	49.3%*
Vendor	6.4%	17.5%*	3.0%	10.1%**
Site	21.7%**	9.9%**	3.8%**	10.7%**
Participant	40.4%*	28.8%*	15.4%**	7.5%*
Residual	28.2%	43.2%	22.3%	19.1%