Table 3.

Odds ratios (estimate (95% confidence interval), relative efficiency^*) of the association between CRC risk and smoke and BMI, by type of models and type of subjects included in the model. CC: ordinal logistic regression model with population-based case and control data; CL: Conditional logistic regression model for family data; Combined: ascertainment adjusted marginalized logistic-normal model. All model adjusted for age, gender and screening history.

Model	Cases (freq.)	Controls (freq.)	Family (freq.)	Smoking		BMI
				Former vs. Never	Current vs. Never	BMI2 vs. BMI1	BMI3 vs. BMI1	BMI4 vs. BMI1
CC	1950	2302	4252	1.20 (1.05–1.38) 1.00	1.65 (1.38–1.99) 1.00	1.16 (0.96–1.40) 1.00	1.33 (1.10–1.59) 1.00	1.75 (1.46–2.11) 1.00
All Siblings
CL	1129	2229	1129	1.06 (0.87–1.29) 0.54	0.92 (0.72–1.18) 0.93	1.09 (0.85–1.39) 0.58	1.16 (0.90–1.49) 0.56	1.32 (1.01–1.73) 0.59
Combined†	2302	4179	4252	1.19 (1.04–1.36) 1.06	1.53 (1.28–1.83) 1.15	1.14 (0.95–1.36) 1.08	1.31 (1.10–1.57) 1.08	1.70 (1.41–2.03) 1.11
All Family Members
CL	1627	5296	1627	1.30 (1.12–1.50) 0.83	1.22 (1.01–1.47) 1.33	1.27 (1.05–1.53) 0.90	1.48 (1.22–1.78) 0.84	1.77 (1.45–2.16) 0.83
Combined‡	2302	7246	4252	1.18 (1.04–1.34) 1.30	1.49 (1.26–1.77) 1.30	1.13 (0.95–1.35) 1.16	1.31 (1.10–1.56) 1.15	1.69 (1.42–2.02) 1.19

^*: Relative efficiency is defined as the ratio of the normalized variance (variance/estimate) for CC versus normalized variance for the design

^†: σ = 1.64 (0.82–3.31)

^‡: σ = 0.53 (0.12–2.45)