Table 2.

Associations of Patient Characteristics with Use in Logistic Regression Model

Variable	Stratum	Odds ratio (95% CI)	Odds ratio (95% CI)	P-value
Age, years	66-70	Reference	Reference
	71-75	0.77 ( 0.64, 0.92 )	0.83 ( 0.68, 1.00 )	0.05
	76-80	0.52 ( 0.43, 0.64 )	0.61 ( 0.49, 0.76 )	<0.0001
	81-85	0.44 ( 0.34, 0.56 )	0.57 ( 0.43, 0.75 )	<0.0001
Race/ethnicity	White	Reference
	Hispanic	1.58 ( 1.19, 2.11 )	1.58 ( 1.15, 2.17 )	0.005
	Black	1.35 ( 1.04, 1.76 )	1.17 ( 0.87, 1.57 )	0.3
	Other	0.71 ( 0.50, 1.02 )	0.81 ( 0.54, 1.21 )	0.31
Marital status	Married	Reference	Reference
	Not married	0.78 ( 0.67, 0.90 )	0.79 ( 0.66, 0.93 )	0.005
	Unknown	0.93 ( 0.69, 1.24 )	0.94 ( 0.68, 1.29 )	0.7
Education level	1st quartilea	Reference	Reference
	2nd quartile	0.96 ( 0.78, 1.19 )	0.94 ( 0.75, 1.17 )	0.56
	3rd quartile	1.24 ( 1.00, 1.54 )	1.19 ( 0.95, 1.50 )	0.13
	4th quartile	1.57 ( 1.27, 1.93 )	1.45 ( 1.15, 1.84 )	0.002
	Unknown	1.52 ( 0.78, 2.94 )	1.48 ( 0.72, 3.02 )	0.29
Income level	1st quartileb	Reference
	2nd quartile	1.18 ( 0.95, 1.46 )
	3rd quartile	1.18 ( 0.95, 1.46 )
	4th quartile	1.47 ( 1.19,1.82 )
	Unknown	1.67 ( 1.08, 2.58 )
Year of diagnosis	2007	Reference	Reference
	2008	0.80 ( 0.63, 1.03 )	0.77 ( 0.59, 1.00 )	0.05
	2009	0.85 ( 0.67, 1.09 )	0.80 ( 0.62, 1.04 )	0.09
	2010	0.72 ( 0.56, 0.92 )	0.70 ( 0.54, 0.91 )	0.007
	2011	0.81 ( 0.64, 1.02 )	0.74 ( 0.58, 0.95 )	0.02
Tumor grade	I	Reference
	II	1.14 ( 0.90, 1.44 )
	III	1.04 ( 0.82, 1.33 )
	IV	0.94 ( 0.64, 1.37 )
	Unknown	1.14 ( 0.85, 1.52 )
Tumor size	≤ 10 mm	Reference
	>10mm	0.97 ( 0.82, 1.16 )
	Unknown	1.09 ( 0.91, 1.31 )
Surgery and radiation	LRT	Reference	Reference
	Lumpectomy	0.41 ( 0.33, 0.50 )	0.48 ( 0.39, 0.60 )	<0.0001
	Mastectomy	0.42 ( 0.35, 0.51 )	0.40 ( 0.33, 0.49 )	<0.0001
Charlson comorbidity	0	Reference
	1	0.97 ( 0.81, 1.16 )
	>1	0.84 ( 0.67, 1.04 )
Cancer registry	California	Reference	Reference
	Connecticut	1.43 ( 0.99, 2.07 )	1.43 ( 0.98, 2.11 )	0.07
	Detroit	2.04 ( 1.39, 3.01 )	2.18 ( 1.44, 3.30 )	0.0002
	Georgia	1.63 ( 1.25, 2.13 )	1.52 ( 1.14, 2.03 )	0.005
	Hawaii	1.37 ( 0.60, 3.15 )	1.69 ( 0.68, 4.19 )	0.26
	Iowa	1.12 ( 0.81, 1.53 )	1.20 ( 0.85, 1.68 )	0.3
	Kentucky	1.21 ( 0.85, 1.71 )	1.18 ( 0.81, 1.71 )	0.39
	Louisiana	2.17 ( 1.49, 3.18 )	2.24 ( 1.48, 3.37 )	0.0001
	New Jersey	1.10 ( 0.85, 1.42 )	1.10 ( 0.84, 1.44 )	0.48
	New Mexico	0.78 ( 0.38, 1.59 )	0.84 ( 0.40, 1.76 )	0.65
	Seattle	0.61 ( 0.40, 0.93 )	0.62 ( 0.40, 0.97 )	0.03
	Texas	1.37 ( 1.09, 1.74 )	1.22 ( 0.94, 1.59 )	0.14
	Utah	1.63 ( 0.90, 2.97 )	1.77 ( 0.94, 3.31 )	0.08

Abbreviations: CI, confidence interval; LRT, lumpectomy followed by radiation therapy.

Bolded values are significant in the multivariable model

^ahighest percentage of residents who graduated from high school

^bhighest median household income