Table 3.

Associations Between Colon Cancer Recurrence and Mortality and Caffeine Consumption

Survival Outcome	Caffeine Intake by Quintiles					Ptrend*
	1	2	3	4	5
DFS
Events and total	78 of 190	84 of 191	62 of 191	73 of 191	68 of 190	—
HR (95% CI), adjusted 1†	1.0	1.02 (0.75 to 1.40)	0.72 (0.51 to 1.00)	0.80 (0.57 to 1.11)	0.65 (0.46-0.91)	.005
HR (95% CI), adjusted 2‡	1.0	1.05 (0.77 to 1.44)	0.74 (0.53 to 1.05)	0.82 (0.59 to 1.14)	0.66 (0.47-0.93)	.006
RFS
Events and total	70 of 190	75 of 191	58 of 191	60 of 191	66 of 190	—
HR (95% CI), adjusted 1†	1.0	0.98 (0.70 to 1.36)	0.73 (0.51 to 1.04)	0.70 (0.50 to 1.00)	0.71 (0.50 to 1.01)	.02
HR (95% CI), adjusted 2‡	1.0	1.05 (0.75 to 1.46)	0.76 (0.54 to 1.09)	0.75 (0.53 to 1.07)	0.76 (0.53 to 1.08)	.04
OS
Events and total	60 of 190	69 of 191	45 of 191	58 of 191	56 of 190	—
HR (95% CI), adjusted 1†	1.0	1.05 (0.74 to 1.50)	0.67 (0.45 to 0.99)	0.83 (0.57 to 1.21)	0.68 (0.46 to 1.00)	.02
HR (95% CI), adjusted 2‡	1.0	1.11 (0.78 to 1.59)	0.68 (0.46 to 1.01)	0.88 (0.61 to 1.28)	0.72 (0.49 to 1.05)	.04

Abbreviations: DFS, disease-free survival; HR, hazard ratio; OS, overall survival; Q1, questionnaire 1 (midway through adjuvant therapy); Q2, questionnaire 2 (6 months after completion of adjuvant therapy); RFS, recurrence-free survival.

^*Two-sided P value. Trend across consumption levels.

^†Adjusting for sex, age, depth of invasion through bowel wall, number of positive lymph nodes, baseline performance status, chemotherapy treatment group, smoking history (Q1, Q2: yes, no, missing), multivitamin (Q1, Q2: consistent user, no, missing), and the following time-varying covariates: total energy intake, alcohol consumption, body mass index, physical activity level, Western dietary pattern, and prudent dietary pattern.

^‡Adjusting for all above covariates plus time-varying sugar-sweetened beverage intake and dietary glycemic load.