Table 2.
Additive and multiplicative effect measure modification by BMI for the multivariable-adjusteda associations between PAH sources/PAH-DNA adducts and postmenopausal breast cancer, Long Island Breast Cancer Study Project, 1996–1997
| BMIb (kg/m2) | PAH exposure | Cases (N) | Controls (N) | Single referent ORs (95% CIs) | Additive ICR (95% CI)c | Stratified ORs (95% CIs) | Multiplicative RORd (95% CI) | LRTd p- value |
|---|---|---|---|---|---|---|---|---|
| Active smoking | ||||||||
| <25 | Never | 159 | 176 | 1.00 | 1.00 | |||
| Ever | 227 | 262 | 1.01 (0.76, 1.35) | 1.01 (0.76, 1.35) | ||||
| ≥25 | Never | 280 | 247 | 1.35 (0.99, 1.77) | 1.00 | |||
| Ever | 324 | 282 | 1.32 (1.00, 1.75) | −0.01 (−0.45, 0.42) | 1.00 (0.78, 1.27) | 0.99 (0.68, 1.44) | 0.9 | |
| ETS from spouse | ||||||||
| <25 | Never | 175 | 209 | 1.00 | 1.00 | |||
| Ever | 197 | 217 | 1.19 (0.89, 1.59) | 1.19 (0.89, 1.59) | ||||
| ≥25 | Never | 269 | 274 | 1.22 (0.93, 1.60) | 1.00 | |||
| Ever | 318 | 238 | 1.74 (1.31, 2.30) | 0.33 (−0.13, 0.79) | 1.43 (1.11, 1.83) | 1.20 (0.82, 1.75) | 0.3 | |
| Grilled/smoked meat | ||||||||
| <25 | 0–54 servings | 130 | 159 | 1.00 | 1.00 | |||
| 55+ servings | 236 | 237 | 1.40 (1.03, 1.91) | 1.40 (1.03, 1.91) | ||||
| ≥25 | 0–54 servings | 189 | 206 | 1.15 (0.84, 1.59) | 1.00 | |||
| 55+ servings | 371 | 287 | 1.87 (1.39, 2.51) | 0.31 (−0.18, 0.80) | 1.62 (1.24, 2.11) | 1.15 (0.77, 1.72) | 0.5 | |
| Synthetic log use | ||||||||
| <25 | Never | 316 | 392 | 1.00 | 1.00 | |||
| Ever | 70 | 44 | 2.09 (1.38, 3.17) | 2.09 (1.38, 3.17) | ||||
| ≥25 | Never | 542 | 474 | 1.44 (1.17, 1.76) | 1.00 | |||
| Ever | 59 | 55 | 1.87 (0.98, 2.21) | −1.06 (−2.09, − 0.02) | 1.02 (0.69, 1.52) | 0.49 (0.28, 0.87) | 0.01 | |
| Vehicular traffic | ||||||||
| <25 | <95th percentile | 290 | 356 | 1.00 | 1.00 | |||
| ≥ 95th percentile | 25 | 21 | 1.44 (0.78, 2.67) | 1.44 (0.78, 2.67) | ||||
| ≥25 | <95th percentile | 487 | 428 | 1.39 (1.13, 1.72) | 1.00 | |||
| ≥95th percentile | 31 | 25 | 1.65 (0.93, 2.92) | −0.18 (−1.46, 1.09) | 1.18 (0.67, 2.08) | 0.82 (0.36, 1.89) | 0.6 | |
| PAH-DNA adducts | ||||||||
| <25 | Non- detectable | 67 | 76 | 1.00 | 1.00 | |||
| Detectable | 156 | 196 | 0.86 (0.57, 1.28) | 0.86 (0.57, 1.28) | ||||
| ≥25 | Non- detectable | 86 | 91 | 1.02 (0.64, 1.61) | 1.00 | |||
| Detectable | 257 | 213 | 1.36 (0.91, 2.01) | 0.49 (0.01, 0.96) | 1.34 (0.94, 1.92) | 1.56 (0.91, 2.68) | 0.1 | |
a
Adjusted for age, alcohol intake, marital status, parity, education, and energy intake
b
BMI at reference
c
ICR, interaction contrast ratio for additive interaction
d
ROR, Ratio of odds ratios; LRT, likelihood ratio test for multiplicative interaction