Table 2. Characteristics of Colon Cancer Patients by Medicare/Medicaid Eligibility Status.

		Medicare Only (N=5,697)		Dually Eligible (N=765)
		N	(%)	N	(%)
Age*	66–70 years	1125	19.75	126	16.47
	71–75 years	1438	25.24	191	24.97
	76–80 years	1384	24.29	158	20.65
	>80 years	1750	30.72	290	37.91
Race*	White	5187	91.05	524	68.5
	African American	510	8.95	241	31.5
Sex*	Male	2613	45.87	228	29.8
	Female	3084	54.13	537	70.2
SEER Stage	In situ	250	4.39	25	3.27
	Local	2140	37.56	272	35.56
	Regional	2292	40.23	339	44.31
	Distant	1015	17.82	129	16.86
Census tract median annual income*	≤$25k	1477	25.93	376	49.15
	$25k to ≤$35k	1797	31.54	256	33.46
	$35k to ≤$45k	1380	24.22	69	9.02
	>$45k	796	13.97	27	3.53
	Missing	247	4.34	37	4.84
		Mean	Std	Mean	Std
Census tract education	Percent <12 year*	0.23	0.1	0.3	0.13
	Percent <college*	0.6	0.09	0.57	0.09
	Percent ≥college*	0.17	0.14	0.13	0.1
		N	(%)	N	(%)
Charlson Index	0*	3848	67.54	416	54.38
	1*	1097	19.26	174	22.75
	2	419	7.35	81	10.59
	3+*	333	5.85	94	12.29
	Myocardial infarction	91	1.6	14	1.83
	Congestive heart failure*	526	9.23	120	15.69
	Peripheral vascular disease	168	2.95	35	4.58
	Cerebrovascular disease	275	4.83	65	8.5
	Obstructive pulmonary disease*	587	10.3	114	14.9
	Diabetes*	841	14.76	167	21.83
	Chronic renal failure*	57	1	17	2.22
	Ulcer*	105	1.84	24	3.14
	Rheumatism	83	1.46	13	1.7
	Alzheimer’s disease*	75	1.32	48	6.27

^*Indicates statistical significant difference between the two groups (p<0.05). Conditions with prevalence less than 1% in either group are not presented: dementia, paralysis, cirrhosis and liver disease.

NOTE: The two-sample t-test was used for continuous variables, the Pearson chi-square test was used for categorical variables, and Fisher’s exact test was used when the cell size is smaller than 5.

SOURCE: Michigan Tumor Resigtry, Medicare and Medicaid fee-for-service claims from 1996 to 2000.