Table 3.

Hazard Ratios and 95% confidence interval (CI) for association between baseline stressful life events and breast cancer by social support in the Women’s Health Initiative Observational Study

	Social Support
Stressful life events	Low Social Support Hazard Ratio (CI)	High Social Support Hazard Ratio (CI)
0	Reference	Reference
1	1.20 (1.00,1.43)	1.08 (0.93,1.25)
2	1.07 (0.88,1.29)	1.09 (0.92,1.28)
3	0.98 (0.79,1.22)	1.17 (0.96,1.43)
4+	0.89 (0.70,1.13)	1.26 (0.99,1.61)

Note: Hazard ratio adjusted for age, education (<high school, high school or equivalent, some college, >=college degree), ethnicity (AI/AN, Asian/PI, Caucasian, Black/AA, Hispanic, Other), diagnosis with diabetes (yes/no), BMI (linear), five-year breast cancer risk from Gail prediction (age, age at menarche, number of previous breast biopsies, presence of atypical hyperplasia on biopsy, age at first childbirth, number of first-degree relatives with a history of breast cancer, and the interactions between biopsies and age and between age at first childbirth and number of affected first-degree relatives) parity (no births,1,2,3,4,5+), history of hysterectomy/bilateral oopherectomy, OC use (never, >0 to <5 years, 5 to <10 years, and 10+ years), HRT use (never, >0 to < 5years, 5 to <10 years, 10+ years), alcohol consumption (none, 0–1/day,1–2/day,2–3/day,>3/day), smoking (never, past, current), fat intake (<30% vs. >=30%), and annual mammography rate during follow-up..

p-value for interaction (p=0.074)

p-value for overall association between breast cancer incidence and stressful life events: High social support (p=0.323); Low social support (p=0.043)