. 2014 Sep 13;14:77. doi: 10.1186/1471-2253-14-77

Table 2.

Key model building steps and associated objective function changes

Basic model		OBJ
1-compartment - no size scaling		8350.263
2-compartment - no size scaling		5804.790
3-compartment – no size scaling		5762.275
3-compartment – no size scaling + individual study centre RUV		5210.072
+BOV		5024.826
+BOV + allometric scaling FFM		4956.866
+BOV + allometric scaling TBW		4942.960
+BOV + allometric scaling NFM		4927.983
+BOV + allometric scaling NFM Ffat_CL = 1		4924.844
+BOV + allometric scaling NFM Ffat_CL = 0		4946.221
+BOV + allometric scaling NFM Ffat_CL = 1 + F_AGEV		4908.588
+BOV + allometric scaling NFM Ffat_CL = 1 + F_AGEV + F_AGECL		4901.989
+BOV + allometric scaling NFM Ffat_CL = 1 + F_AGEV + F_AGECL + F_SEXCL		4900.663
+BOV + allometric scaling NFM Ffat_CL = 1 + F_AGEV + F_AGECL + F_PREGCL	-F_SEXCL	4893.125
+BOV + allometric scaling NFM Ffat_CL = 1 + F_AGEV + F_AGECL + F_PREGCL + F_ICCL		4888.551
+BOV + allometric scaling NFM Ffat_CL = 1 + F_AGEV + F_AGECL + F_PREGCL + F_ICVOL	-F_ICCL	4876.427
+BOV + allometric scaling NFM Ffat_CL = 1 + F_AGEV + F_AGECL + F_PREGCL + F_ICV + F_HDUCL		4875.677
+BOV + allometric scaling NFM Ffat_CL = 1 + F_AGEV + F_AGECL + F_PREGCL + F_ICV + F_ORTHOV	-F_HDUCL	4839.712
+BOV + allometric scaling NFM Ffat_CL = 1 + F_AGEV + F_AGECL + F_PREGCL + F_ICV + F_ORTHOV + F_ABDCL		4827.174
+BOV + allometric scaling NFM Ffat_CL = 1 + F_AGEV + F_PREGCL + F_ICV + F_ORTHOV + F_ABDCL	-F_AGECL	4827.284

An OBJ decrease of 6.635 (p < 0.01) for these nested models was deemed significant for covariate inclusion.

[BOV = between occasion variability; RUV = residual unexplained variability; FFM = fat free mass; TBW = total body weight; NFM = normal fat mass; CL = clearance; abd = abdominal surgery; preg = pregnant; IC = intensive care; HD = high dependency care; ortho = orthopaedic surgery].