Table 2.

Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) from Cox proportional hazards modeling of body mass index, menopausal status and age at baseline

Model		HRb	95% CI	P	ΔLLc
I	Log body mass indexa (per 5 kg/m2)	1.28	0.91, 1.81	0.2	2.38
	Age at baseline, years	0.98	0.96, 1.00	0.1
	Menopause, no/yes	1.12	0.88, 1.43	0.4
II	Log body mass indexa (per 5 kg/m2)	0.13	0.03, 0.56	0.006	7.36
	Age at baseline, years	0.98	0.96, 1.00	0.1
	Menopause, no/yes	1.12	0.88, 1.44	0.4
	Log body mass index (per 5 kg/m2) × Age at baseline, years	1.05	1.02, 1.08	0.002
III	Log body mass indexa (per 5 kg/m2)	0.68	0.41, 1.01	0.1	9.14
	Age at baseline, years	0.98	0.96, 1.00	0.1
	Menopause, no/yes	1.12	0.87, 1.44	0.4
	Log body mass index (per 5 kg/m2) × Menopause, no/yes	3.68	1.86, 7.28	< 0.001
IV	Log body mass indexa (per 5 kg/m2)	0.40	0.06, 2.89	0.4	9.32
	Age at baseline, years	0.98	0.96, 1.00	0.1
	Menopause, no/yes	1.12	0.88, 1.44	0.4
	Log body mass index (per 5 kg/m2) × Age at baseline, years	1.01	0.97, 1.06	0.6
	Log body mass index (per 5 kg/m2) × Menopause, no/yes	2.91	0.91, 9.31	0.07

To account for clustering by family, robust 95% CIs are reported

LL log likelihood

^aAdjusted for log baseline age as a quadratic

^bAdjusted for history of benign breast disease, race/ethnicity, and education; stratified by year of birth (10-year groups) and study site

^cChange in LL from the base model that includes benign breast disease, race/ethnicity, and education