Table 4.

The effect modification of lung cancer risk between raw garlic consumption and major risk factors

VariablesRaw garlic consumptionCase/controlCrude OR (95% CI)Adjusted OR (95% CI)a
Pack-years of smoking
 ≥30 yNo381/7531.001.00
 ≥30 yYesb387/8420.91 (0.77–1.08)0.68 (0.56–0.83)
 <30 yNo129/5750.44 (0.35–0.56)0.38 (0.30–0.48)
 <30 yYes133/5130.51 (0.41–0.64)0.34 (0.26–0.43)
 NeverNoc194/10950.35 (0.29–0.43)0.21 (0.17–0.27)
 NeverYes200/7650.52 (0.42–0.63)0.24 (0.19–0.31)
InteractionaAdditive:RERI = −0.40 (95% CI, −0.60–−0.20)
AP = −0.21 (95% CI, −0.32–−0.09)
SI = 0.70 (95% CI, 0.57–0.85)
Multiplicative:ROR = 0.78 (95% CI, 0.67–0.90)
High-temperature cooking oil
 YesNob284/7361.001.00
 YesYes229/6130.97 (0.79–1.19)0.74 (0.59–0.92)
 NoNo420/1,6870.65 (0.54–0.77)0.71 (0.59–0.85)
 NoYesc491/1,5070.84 (0.71–1.00)0.68 (0.56–0.82)
InteractionaAdditive:RERI = 0.35 (95% CI, 0.04–0.65)
AP = 0.23 (95% CI, 0.04–0.43)
SI = 3.56 (95% CI, 0.42–30.46)
Multiplicative:ROR = 0.77 (95% CI, 0.59–1.00)
Consumption of fried food
 YesNob249/7091.001.00
 YesYes524/1,2951.15 (0.97–1.38)0.91 (0.74–1.11)
 NoNo455/1,7140.76 (0.63–0.90)0.82 (0.68–1.00)
 NoYesc196/8250.68 (0.55–0.84)0.61 (0.48–0.76)
InteractionaAdditive:RERI = −0.20 (95% CI, −0.59–0.18)
AP = −0.12 (95% CI, −0.36–0.11)
SI = 0.76 (95% CI, 0.47–1.23)
Multiplicative:ROR = 1.23 (95% CI, 0.94–1.61)
  • aAdjusted on age (continuous), gender (male = 1, female = 0), education level (illiteracy = 1, primary = 2, middle = 3, high = 4, college = 5), income (Yuan/year) 10 years ago (continuous), BMI (continuous), family history of lung cancer (yes = 1, no = 0), pack-year of smoking (continuous, except for variable of ever smoking), ethanol consumption (mL/week, continuous), and study area (Dafeng = 1, Ganyu = 2).

  • bThe joint effects category for further estimation of additive interaction.

  • cThe reference category for measures of interaction on additive scale.