Table 3.

Multivariable binary logistic regression model of variables associated with bilateral first-line mastectomy

		p value	Odds ratio	95% CI
MRI referral	noMRI	Reference	–	–
	Screening MRI	< 0.001	29.2	12.6–67.6
	Diagnostic MRI	0.004	3.6	1.5–8.7
	Preoperative MRI	< 0.001	6.8	3.7–12.5
Breast cancer risk	Familial breast cancer risk	0.001	3.9	1.8–8.5
Hormonal status	Postmenopausal	Reference	–	–
	Premenopausal	0.079	1.4	1.0–2.1
	Perimenopausal	0.376	1.3	0.7–2.4
Lesion features at US	No observable lesion	Reference	–	–
	Single focus	0.140	1.5	0.9–2.7
	Multifocal	0.010	2.5	1.2–5.0
	Multicentric	< 0.001	7.5	3.5–16.4
Core-needle or vacuum-assisted biopsy	Lobular component	0.001	2.1	1.4–3.3

CI, confidence interval; US, ultrasonography; MRI, magnetic resonance imaging