Table 4.

Multivariable Hazard Ratio for Lung Cancer Associated With Soy Food Intake (per 5-g/day Increment), According to Selected Covariates, Shanghai Women's Health Study, 1997–2008^a

	No. of Cases	Hazard Ratiob	95% Confidence Interval	P Value	Pinteraction
Age at baseline, years
<50 (median, 50)	76	0.93	0.82, 1.05	0.26	0.53
≥50	294	0.92	0.87, 0.98	0.01
Age at menopause at baseline, yearsc
<49 (median, 49)	148	0.98	0.91, 1.05	0.57	0.01
≥49	138	0.88	0.80, 0.97	0.008
Years of reproduction at baselinec
<34 (median, 34)	169	0.98	0.91, 1.05	0.49	0.04
≥34	117	0.86	0.78, 0.96	0.006

^a The first year of observation was omitted from the analysis.

^b Multivariable Cox proportional hazards models were adjusted for age, education, cigarette smoking, alcohol consumption, physical activity, body mass index, menopausal status, family history of lung cancer among first-degree relatives, and average intakes of total calories, fruits, nonsoy vegetables, red meat, and nonsoy calcium and were stratified on birth year. Usual soy food intake on a dry-weight basis was measured by averaging intakes from the first and second frequency food questionnaires.

^c Restricted to postmenopausal women.