Table 2.

Invasive colorectal cancer outcome: addition of groupings of potential confounding variables

	White	African–American HR (95% CI)	Hispanic HR (95% CI)	Native American HR (95% CI)	Asian/Pacific Islander HR (95% CI)	Wald χ	P-valuea
Model 1b	1.0 (ref)	1.16 (0.99, 1.34)	0.73 (0.54, 0.97)	0.99 (0.49, 1.98)	0.81 (0.59, 1.09)	11.07	0.03
Model 1 + education (≥HS vs. <HS)	1.0 (ref)	1.17 (1.01, 1.36)	0.76 (0.57, 1.02)	1.01 (0.50, 2.03)	0.79 (0.58, 1.08)	10.64	0.03
Model 1 + history of diabetes	1.0 (ref)	1.12 (0.96, 1.30)	0.71 (0.54, 0.95)	0.95 (0.47, 1.90)	0.80 (0.59, 1.08)	10.13	0.04
Model 1 + lifestyle factors (BMI, physical  activity, smoking, alcohol)	1.0 (ref)	1.09 (0.92, 1.28)	0.75 (0.55, 1.01)	0.93 (0.44, 1.95)	0.92 (0.67, 1.25)	5.26	0.26
Model 1 + NSAID use/duration	1.0 (ref)	1.15 (0.99, 1.34)	0.72 (0.54, 0.96)	0.99 (0.49, 1.99)	0.84 (0.61, 1.15)	11.14	0.03
Model 1 + dietary factors (total energy,  fiber, red meat, fruits and vegetables)	1.0 (ref)	1.11 (0.94, 1.29)	0.73 (0.54, 0.98)	1.03 (0.51, 2.06)	0.79 (0.57, 1.09)	8.49	0.08
Model 1 + total calcium intake	1.0 (ref)	1.08 (0.92, 1.26)	0.71 (0.53, 0.96)	1.02 (0.51, 2.05)	0.77 (0.56, 1.06)	8.93	0.06
Model 1 + screening, polyp removal and family history	1.0 (ref)	1.19 (1.01, 1.40)	0.70 (0.51, 0.96)	1.05 (0.50, 2.20)	0.83 (0.61, 1.14)	11.32	0.02
Model 1 + hormone therapy use	1.0 (ref)	1.09 (0.93, 1.26)	0.71 (0.53, 0.94)	0.98 (0.49, 1.96)	0.81 (0.60, 1.11)	8.97	0.06

^aFrom a Wald χ² 4 degrees of freedom test of the main effect of race/ethnicity

^bAdjusted for age, and stratified on WHI trial and extension study participation.