Appendix Table 1.

Regression: Probability of receipt of adjuvant therapy among those with surgical resection, 2003–05.

Patient Characteristics	β	(SE)	p	OR	95% CI
Gender (ref = Male)
Female	−0.100	0.078	0.202	0.905	(0.776–1.055)
Race (ref = Caucasian)
African American	−0.198	0.193	0.304	0.820	(0.562–1.197)
Other/Unknown	0.309	0.226	0.172	1.362	(0.874–2.122)
Age (ref = 65–69)
70–74	−0.613 ^***	0.155	<.001	0.542	(0.400–0.734)
75–79	−1.011 ^***	0.151	<.001	0.364	(0.271–0.490)
80–84	−2.002 ^***	0.157	<.001	0.135	(0.099–0.184)
85+	−3.064 ^***	0.166	<.001	0.047	(0.034–0.065)
Education¹ (ref=Quartile 1)
Quartile 2: low–med education	−0.009	0.112	0.935	0.991	(0.795–1.235)
Quartile 3: med–high education	−0.057	0.107	0.595	0.945	(0.767–1.165)
Quartile 4: highest education	0.066	0.116	0.572	1.068	(0.850–1.341)
Primary site of tumor (ref=Cecum,
Flexures, Transverse/Descending	−0.158 ^*	0.092	0.087	0.854	(0.713–1.023)
Large intestine/NOS	0.291	0.271	0.283	1.337	(0.787–2.273)
Sigmoid	−0.064	0.093	0.490	0.938	(0.782–1.125)
Tumor grade (ref=poorly differentiated)
Well-differentiated	0.005	0.214	0.980	1.005	(0.660–1.530)
Moderately differentiated	−0.070	0.089	0.429	0.932	(0.783–1.109)
Unknown	−0.461 ^**	0.198	0.020	0.631	(0.428–0.931)
Year of Diagnosis (ref=2003)
2004	−0.169 ^*	0.090	0.058	0.844	(0.708–1.006)
2005	−0.160 ^*	0.094	0.088	0.853	(0.710–1.024)
Dual eligibility (ref=no)
Yes	−0.726 ^***	0.105	<.001	0.484	(0.394–0.594)
Comorbidity conditions (ref=no, for
Liver disease	0.328	0.563	0.560	1.388	(0.460–4.184)
Rheumatoid disease or AIDs	0.461	0.329	0.161	1.585	(0.832–3.019)
Renal disease	−0.098	0.366	0.788	0.906	(0.442–1.857)
Dementia or paralysis	−0.410	0.289	0.156	0.664	(0.376–1.170)
CHF or acute MI or CVD or COPD	−0.563 ^***	0.089	<.001	0.570	(0.479–0.678)
Neuropathy	−0.159	0.262	0.546	0.854	(0.511–1.427)
Diabetes	−0.148	0.101	0.144	0.863	(0.708–1.052)

*Organization characteristics (of treating hospital)*

Proportion of claims from CCOP-affiliated MD or Hospital	2.550 ^***	0.285	<.001	12.806	(7.319–22.406)
Any Direct Cooperative group affiliation (ref=no)	−0.184 ^*	0.099	0.064	0.832	(0.685–1.011)
Any Medical School Affiliation (ref=unaffiliated)	0.011	0.116	0.928	1.011	(0.805–1.268)
NCI-center affiliated (ref=no)	0.021	0.798	0.979	1.021	(0.214–4.875)

*Intercept*	2.588 ^***	0.223	<.001	13.296	(8.585–20.594)

Estimates of Model Fit
QIC	4380.10
QICu	4367.54
Sample Size	4,054

Significance:

.10;

^**

.05;

^***

.01

Proportion of patient’s census tract population with high school education or greater

-SEER regions were examined but are not reported.