Table 3.
Exposure prevalence, hazard ratios for CRC incidence by exposure level, and fractions of CRC incidence attributable to exposure to behavioral risk factors by other behavioral risk factors
| Effect modifier | Subgroup 1 |
Subgroup 2 |
Subgroup 3 |
P† | |||
|---|---|---|---|---|---|---|---|
| Behavioral risk factor | PR, % | HR (95% CI)* | PR, % | HR (95% CI)* | PR, % | HR (95% CI)* | |
| Smoking status | Never smoker | Former smoker | Current smoker | ||||
| BMI, kg/m2 | |||||||
| 1. <18.5 | 2 | 0.89 (0.57 to 1.39) | 1 | 1.19 (0.73 to 1.93) | 2 | 1.22 (0.62 to 2.41) | |
| 2. 18.5–24.9 | 39 | 1 | 27 | 1 | 38 | 1 | |
| 3. 25.0–29.9 | 34 | 1.16 (1.04 to 1.30) | 39 | 1.04 (0.92 to 1.18) | 34 | 1.12 (0.85 to 1.47) | |
| 4. ≥30 | 25 | 1.40 (1.22 to 1.60) | 34 | 1.25 (1.08 to 1.44) | 26 | 1.02 (0.72 to 1.46) | |
| PAF (3, 4 → 2) | 13.5 (7.4 to 19.2) | 9.1 (0.6 to 16.8) | 4.4 (–12.2 to 18.5) | P1-2 = .38, P1-3 = .27, P2-3 = .59 | |||
| PAF (4 → 3) | 5.1 (1.4 to 8.7) | 6.3 (1.3 to 11.0) | –2.3 (–12.1 to 6.6) | P1-2 = .71, P1-3 = .15, P2-3 = .11 | |||
| Alcohol consumption, drinks/d | |||||||
| 1. ≤2 | 90 | 1 | 77 | 1 | 69 | 1 | |
| 2. >2 | 10 | 1.15 (0.96 to 1.38) | 23 | 1.37 (1.21 to 1.55) | 31 | 1.55 (1.19 to 2.03) | |
| PAF (2 → 1) | 1.6 (–0.6 to 3.6) | 8.1 (4.7 to 11.5) | 15.0 (4.8 to 24.1) | P1-2 = .001, P1-3 < .001, P2-3 = .19 | |||
| BMI, kg/m2 | 18.5–24.9 | 25.0–29.9 | ≥30 | ||||
| Smoking status | |||||||
| 1. Never | 58 | 1 | 51 | 1 | 47 | 1 | |
| 2. Former | 24 | 1.31 (1.15 to 1.49) | 34 | 1.18 (1.05 to 1.33) | 38 | 1.19 (1.01 to 1.38) | |
| 3. Current | 17 | 1.34 (1.08 to 1.66) | 15 | 1.30 (1.05 to 1.61) | 15 | 0.99 (0.72 to 1.36) | |
| PAF (2, 3 → 1) | 12.4 (6.4 to 18.1) | 10.2 (3.9 to 16.0) | 6.5 (–2.3 to 14.5) | P1-2 = .60, P1-3 = .25, P2-3 = .48 | |||
| PAF (3 → 1) | 5.5 (1.1 to 9.8) | 4.4 (0.4 to 8.2) | –0.2 (–4.9 to 4.3) | P1-2 = .69, P1-3 = .07, P2-3 = .13 | |||
| Alcohol consumption, drinks/d | |||||||
| 1. ≤2 | 84 | 1 | 80 | 1 | 82 | 1 | |
| 2. >2 | 15 | 1.34 (1.13 to 1.59) | 20 | 1.34 (1.17 to 1.54) | 18 | 1.27 (1.04 to 1.55) | |
| PAF (2 → 1) | 5.5 (2.0 to 8.9) | 6.8 (3.3 to 10.1) | 4.9 (0.4 to 9.5) | P1-2 = .61, P1-3 = .84, P2-3 = .51 | |||
| Alcohol consumption, drinks/d | ≤2 | >2 | |||||
| Smoking status | |||||||
| 1. Never | 58 | 1 | 29 | 1 | |||
| 2. Former | 29 | 1.21 (1.11 to 1.31) | 42 | 1.43 (1.17 to 1.74) | |||
| 3. Current | 13 | 1.18 (1.01 to 1.39) | 29 | 1.59 (1.20 to 2.11) | |||
| PAF (2, 3 → 1) | 8.0 (4.3 to 11.6) | 25.8 (12.8 to 36.8) | P1-2 = .005 | ||||
| PAF (3 → 1) | 2.3 (–0.04 to 4.5) | 12.4 (4.3 to 19.8) | P1-2 = .01 | ||||
| BMI, kg/m2 | |||||||
| 1. <18.5 | 2 | 1.05 (0.77 to 1.43) | 1 | 1.02 (0.42 to 2.48) | |||
| 2. 18.5–24.9 | 36 | 1 | 31 | 1 | |||
| 3. 25.0–29.9 | 35 | 1.11 (1.01 to 1.21) | 40 | 1.09 (0.89 to 1.32) | |||
| 4. ≥30 | 28 | 1.32 (1.19 to 1.47) | 29 | 1.22 (0.96 to 1.54) | |||
| PAF (3, 4 → 2) | 11.5 (6.4 to 16.3) | 8.8 (–4.1 to 20.1) | P1-2 = .69 | ||||
| PAF (4 → 3) | 5.3 (2.2 to 8.4) | 3.4 (–3.4 to 9.7) | P1-2 = .60 | ||||
*
Adjusted for age, sex, study, smoking, BMI, and alcohol consumption. Some percentages do not add up to 100 because of rounding. BMI = body mass index; CI = confidence interval; CRC = colorectal cancer; HR = hazard ratio; PAF = population attributable fraction; PR = prevalence.
†
P value for difference in PAF estimates between subgroups.