Table 2.

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

WhiteAfrican–AmericanHispanicNative AmericanAsian/Pacific Islander
HR (95% CI)HR (95% CI)HR (95% CI)HR (95% CI)Wald χP-valuea
Model 1b1.0 (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)11.070.03
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)10.640.03
Model 1 + history of diabetes1.0 (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)10.130.04
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)5.260.26
Model 1 + NSAID use/duration1.0 (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)11.140.03
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)8.490.08
Model 1 + total calcium intake1.0 (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)8.930.06
Model 1 + screening, polyp removal and family history1.0 (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)11.320.02
Model 1 + hormone therapy use1.0 (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)8.970.06
  • 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.