Table 6. Regression of log-transform of CoV for (I) x-, (II) y-, and (III) z-dimensions measurements for algorithm #1.

Nodule characteristics	Univariate				Multivariable
	Estimate (β)	Std. error	P value		Estimate (β)	Std. error	P value
x-measurement (right to left across patient)
Volume (mm3)	−0.0002	0.0001	0.09		−0.0003	0.0001	0.06
Nodule location
Upper/middle lobe	Ref.				Ref.
Lower lobe	0.22	0.11	0.06		0.17	0.11	0.13
Blood vessel attachment	−0.04	0.12	0.71		0.10	0.12	0.40
Costal pleural attachment	0.72	0.19	0.0003		0.72	0.22	0.001
y-measurement (anterior to posterior)
Volume (mm3)	−0.0005	0.0001	<0.001		−0.0005	0.0001	<0.001
Nodule location
Upper/middle lobe	Ref.				Ref.
Lower lobe	0.14	0.11	0.23		0.04	0.12	0.73
Blood vessel attachment	−0.10	0.12	0.41		0.02	0.12	0.84
Costal pleural attachment	0.09	0.23	0.70		0.18	0.22	0.42
z-measurement (superior to inferior)
Volume (mm3)	−0.0003	0.0002	0.11		−0.0001	0.0002	0.52
Nodule location
Upper/middle lobe	Ref.				Ref.
Lower lobe	0.36	0.13	0.01		0.37	0.14	0.01
Blood vessel attachment	−0.21	0.13	0.12		−0.20	0.14	0.16
Costal pleural attachment	0.33	0.24	0.16		0.18	0.26	0.49

Reference categories were absent of blood vessel attachment and absent of costal pleural attachment. CoV, coefficient of variation; Std., standard.