Table 2.

Hazard ratios (HR) and 95% confidence intervals (95% CI) of breast cancer death by quartile of dietary folate intake among 3,116 invasive breast cancer cases in the Swedish mammography cohort

	Quartile of folate intake (μg/d)				Ptrenda
	<190	190–217	218–245	≥246
Person-years	6210	6453	6463	6590
Breast cancer deaths	110	105	82	84
Age-adjusted model	1.00	0.94 (0.72–1.23)	0.73 (0.55–0.97)	0.72 (0.54–0.96)	0.009
Covariate-adjusted modelb	1.00	1.00 (0.77–1.31)	0.74 (0.56–0.99)	0.76 (0.57–1.01)	0.02
Covariate-adjusted model + clinical characteristicsc	1.00	1.01 (0.77–1.33)	0.77 (0.57–1.02)	0.78 (0.58–1.03)	0.03
Total deaths	240	218	196	206
Age-adjusted model	1.00	0.90 (0.75–1.08)	0.79 (0.65–0.95)	0.74 (0.62–0.89)	0.0007
Covariate-adjusted modelb	1.00	0.95 (0.79–1.15)	0.80 (0.66–0.97)	0.78 (0.65–0.94)	0.003
Covariate-adjusted model + clinical characteristicsc	1.00	0.98 (0.81–1.18)	0.80 (0.66–0.96)	0.79 (0.66–0.96)	0.004

^aDetermined using category medians

^bCox proportional hazard model adjusted for age (continuous), energy intake (continuous), education level (primary, high school, university), marital status (single, married, divorced, widowed, living with partner), menopausal status at diagnosis, (premenopausal, postmenopausal, unknown), body mass index (<20, 20–24.9, 25–29.9, ≥30 kg/m²), alcohol intake (non-drinker, <3.4, 3.4–9.9, ≥10 g/d), and calendar year of diagnosis (continuous)

^cCox proportional hazard model adjusted for the variables above plus disease stage (I, II, III/IV), grade (I, II, III), radiation treatment (yes/no), and chemotherapy and/or hormonal treatment (no chemotherapy or hormonal treatment, hormonal therapy and no chemotherapy, chemotherapy and no hormonal therapy, and hormonal therapy and chemotherapy)