Fig. 2
From: Breast cancer risk factors and mammographic density among high-risk women in urban China
Associations of selected risk factors with mammographic density by province: a age, b education, c BMI, d weight, e height, f parity, g age at first full-term birth, h menopausal status, and i age at menopause. Province-specific ORtrend and Ptrend for having dense (BI-RADS, 3–4) compared to non-dense breast (BI-RADS, 1–2) were estimated using multivariable logistic regression adjusted for age (per 2-years), education (none to elementary, middle school, high school, college + ), BMI (per 2 kg/m2), age at menarche (<13, 13-14, 15+years old), parity (parous vs. nulliparous), and menopausal status (premenopausal and postmenopausal). Age at full-term birth (<25, 25–26, 27–28, 29+) was estimated only for parous women with additional adjustment for breastfeeding duration (no breastfeeding, 1–6 months, 7–12 months, 13 months+). OR for age at menopause (<49, 49-50, 51+) was estimated only for postmenopausal women. For categorical variables (education, age at first full term birth, and age at menopause), linear trend in association (Ptrend) was tested by treating each factor as an ordinal variable. Meta-analysis was performed based on the random-effects model
