The association of area-level social class and tobacco use with adverse breast cancer characteristics among white and black women: evidence from Maryland, 1992–2003

Table 4 Multi-level random effects logistic regression model individual and area-level factors associated with large tumor size at diagnosis for breast cancer among white and black women in Maryland, 1999–2003 (17,248 women in 3413 census blockgroups, Maryland cancer registry)

	Model 1		Model 2		Model 3		Model 4		Model 5
Fixed Effects	O.R.	95% CI	O.R.	95% CI	OR	95% CI	O.R.	95% CI	O.R.	95% CI
Intercept	0.61	(0.58,0.63)	0.63	(0.61,0.65)	0.64	(0.61,0.66)	0.50	(0.42,0.60)	0.48	(0.38,0.59)
Individual Level
Age	0.99	(0.99,0.99)	0.99	(0.99,0.99)	0.99	(0.99,0.99)	0.99	(0.99,0.99)	0.99	(0.99,0.99)
Black Race	1.59	(1.47,1.71)	1.45	(1.34,1.56)	1.49	(1.37,1.61)	1.56	(1.34,l.70)	1.54	(1.41,1.69)
Census Blockgroup Level
Social Class			0.87	(0.84,0.90)	0.84	(0.81,0.87)	0.87	(0.83,0.92)	0.88	(0.83,0.93)
Class*Black Race					1.14	(1.05,1.23)	1.10	(1.01,1.19)	1.09	(1.00,1.18)
Tobacco Spending (per $100)							1.03	(1.01,1.06)	1.04	(1.01,1.07)
Tobacco*Black Race									0.97	(0.92,1.03)
Random Effects	Estimate	P Value	Estimate	P Value	Estimate	P Value	Estimate	P Value	Estimate	P Value
Blockgroup Level Variance	0.04203	<0.0001	0.02145	<0.0001	0.01863	<0.0001	0.01487	<0.0001	0.01462	<0.0001
Residual ICC	0.01261	0.01	0.00648	0.12	0.00563	0.15	0.0045	0.21	0.00442	0.21

Among women whose tumor size at diagnosis was reported, those with tumors > 2 cm, compared to those with tumor size < = 2 cm.
Age in years, centered at the median age of 59. Year of Diagnosis is centered at 1997.
Census blockgroup social class index standardized by subtracting median (272), dividing by the standard deviation (37.7).
Census blockgroup estimated tobacco spending is average per household, in units of $100, and is centered at median (7).
Significance of variance of the blockgroup-level random intercept, calculated with the Wald X ² test.
Significance of the residual intraclass (within blockgroup) correlation based on the likelihood ratio X ² test.

ISSN: 1476-072X