Table 5:

Association (HR + 95% CI’s) of SES Index by Study Site location adjusted for BMI% and race/ethnicity for onset of breast development and age at menarche, BCERP 2004–2015.

	Age at Breast Stage B2						Age at Menarche
	New York City		Cincinnati Area*		San Francisco Area		New York City		Cincinnati Area*		San Francisco Area
	HR	95% CI	HR	95% CI	HR	95% CI	HR	95% CI	HR	95% CI	HR	95% CI
SES Index
Quintile 1 (Lowest)	0.89	0.65–1.22	0.85	0.43–1.70	1.68	1.09–2.61	0.89	0.59–1.33	1.42	0.82–2.46	1.31	0.76–2.26
Quintile 2	1.13	0.81–1.57	0.58	0.29–1.15	1.38	0.97–1.97	1.07	0.71–1.64	0.84	0.50–1.42	1.12	0.79–1.59
Quintile 3	-		1.45	0.88–2.37	1.12	0.87–1.45	-		1.31	0.90–1.89	1.01	0.74–1.38
Quintile 4	-		1.41	0.94–2.13	0.99	0.79–1.25	-		1.14	0.81–1.59	1.02	0.81–1.30
Quintile 5 (ref)	1		1		1		1		1		1
p-value for trend	0.998		0.297		0.013		0.371		0.731		0.397
BMI%
>=85	3.74	2.77–5.04	5.12	3.36–7.80	1.47	1.17–1.85	2.13	1.56–2.92	2.42	1.74–3.36	2.09	1.61–2.72
50 to <85	1.72	1.26–2.36	2.70	1.86–3.92	1.19	0.97–1.47	2.31	1.63–3.27	2.41	1.77–3.28	1.43	1.15–1.78
<50 (ref)	1		1		1		1		1		1
Race/Ethnicity
Black	1.06	0.82–1.36	2.37	1.57–3.56	1.73	1.32–2.27	0.55	0.41–0.74	1.95	1.41–2.69	1.57	1.19–2.07
Hispanic	1’		-		0.89	0.69–1.16	1		-		1.20	0.88–1.63
Asian	-		-		1.06	0.77–1.45	-		-		1.12	0.82–1.52
White	-		1		1		-		1		1

• Asians and Hispanics were not included for Cincinnati Area due to small numbers