Table 1.

Models comparing breast cancer surgical outcomes in subjects who had pre-operative MRI versus those who did not have MRI

Model comparing surgical outcomes in those who had MRI versus those who did not have MRI [Number of studies in model]	Number of subjects† included in analysis		Pooled Odds Ratio [Referent: No MRI]			Pooled OR stratified by study-level aggregate age§ [Referent: No MRI]
						Median or mean age < 55 years§		Median or mean age ≥ 55 years§
	MRI	No MRI	OR	95% CI	P value*	OR (95% CI)	P*	OR (95% CI)	P*
Surgical treatment: receipt of mastectomy [15 studies]	15274	70701	1.39	1.23, 1.57	< 0.001	1.33 (1.09, 1.62)	0.005	1.43 (1.21, 1.68)	< 0.001
Re-excision or further local excision, where received BCS [7 studies]	2342	4415	1.19	0.85, 1.66	0.316	1.48 (0.74, 3.00)	0.268	1.08 (0.73, 1.60)	0.712
Positive margins or incomplete excision, where received initial BCS [ 6 studies]	2333	4353	1.17	0.89, 1.55	0.26	2.66 (0.98, 7.25)	0.056	1.08 (0.88, 1.31)	0.467
Any reoperation [10 studies]	6351	23927	0.89	0.72, 1.10	0.272	0.88 (0.31, 2.56)	0.818	0.94 (0.78, 1.12)	0.473
Receipt of contralateral prophylactic mastectomy [3 studies]	15461	110624	1.91‡	1.25, 2.91	0.003	NA**	-	NA**	-

^†Subject numbers varied according to the number of studies contributing outcomes data to each model

^*P value for model comparing estimates of each outcome in those who had MRI relative to those who did not have MRI (referent group)

^§Estimates stratified around the median value [55.1 years] for study-level median or mean age

^‡Pooled OR in model calculated directly from adjusted study-specific ORs

^**NA: not applicable (analysis based on three studies that did not report study-level median or mean age)