Table 2:

Effect of pre-existing dementia on cancer-specific survival for patients with Stage III colon cancer based on Cox proportional hazards models.

Variables	Hazard Ratio (95% CI)
	Model 1	Model 2
Presence of pre-existing dementia
No dementia	Reference	Reference
Dementia (Any evidence)	1.45 (1.29, 1.63) a	-
Dementia (both diagnosis and prescription)	-	1.23 (0.99, 1.52) b
Dementia (diagnosis only)		1.59 (1.35, 1.87) b
Dementia (prescription only)		1.93 (1.14, 3.28) b
Age
65–84	0.59 (0.53, 0.66)	0.58 (0.52, 0.65)
84+	Reference	Reference
Gender
Male	1.00 (0.91, 1.10)	1.00 (0.91, 1.09)
Female	Reference	Reference
Race
White	Reference	Reference
Black	0.94 (0.80, 1.10)	0.93 (0.79, 1.09)
Hispanic	0.88 (0.62, 1.25)	0.86 (0.61, 1.23)
Asian	0.7t6 (0.59, 0.96)	0.75 (0.59, 0.95)
Marital status
Married	0.94 (0.80, 1.10)	0.94 (0.80, 1.11)
Single	Reference	Reference
Insurance types
Insured, NOS	0.70 (0.48, 1.02)	0.69 (0.47, 1.01)
Medicaid/Low income	1.51 (0.98, 2.32)	1.49 (0.97, 2.29)
Medicare	1.14 (1.03, 1.26)	1.15 (1.04, 1.27)
Private/Government	Reference	Reference
Not insured	0.94 (0.35, 2.53)	0.94 (0.35, 2.52)
Median income
Low	Reference	Reference
Median	1.03 (0.91, 1.16)	1.02 (0.91, 1.15)
High	1.07 (0.93, 1.24)	1.08 (0.93, 1.24)
Less than 12 years education
Low percentage	0.78 (0.67, 0.90)	0.78 (0.68, 0.91)
Middle percentage	0.93 (0.83, 1.05)	0.94 (0.83, 1.06)
High percentage	Reference	Reference
Grade
Grade I	Reference	Reference
Grade II	1.10 (0.87, 1.39)	1.10 (0.88, 1.39)
Grade III	2.08 (1.65, 2.63)	2.10 (1.66, 2.65)
Grade IV	2.57 (1.91, 3.48)	2.56 (1.90, 3.46)
Unknown	2.39 (1.74, 3.29)	2.43 (1.76, 3.34)
Charlson comorbidity index
No comorbidity	1.00 (0.90, 1.11)	0.99 (0.89, 1.10)
1	1.01 (0.90, 1.13)	1.00 (0.89, 1.13)
2+	Reference	Reference
Chemotherapy
No	Reference	Reference
Yes	0.56 (0.50, 0.61)	0.55 (0.50, 0.61)

^aThe overall effect of pre-existing dementia on survival.

^bThe effect of source of evidence of pre-existing dementia on survival.