Methods:

The study cohort was comprised of 44,174 subjects from the Women’s Health Initiative for whom HF outcomes were centrally adjudicated from enrollment beginning in 1993 through September 2014. The investigators evaluated the incidence of HF hospitalization in this cohort. They compared HF hospitalization to self-reported reproductive factors including number of live births, age at first pregnancy lasting at least 6 months, and total reproductive duration (time to menarche to menopause). Selected covariates included age at screening, household income, education level, ethnicity, U.S. region, body mass index (BMI), hypertension (defined by self-report, systolic blood pressure >140 mm Hg or diastolic blood pressure >90 mm Hg at screening, or use of antihypertensive medication), diabetes (defined by fasting glucose >126 mg/dl or use of diabetes medication), hyperlipidemia requiring the use of medication, smoking status, history of breastfeeding for ≥1 month, history of pregnancy loss, prior hysterectomy, and usage of oral contraception or menopausal hormone therapy. The primary outcome for this analysis was the time to development of a first hospitalization for definite or probable acute decompensated HF or newly diagnosed stable HF. They used Cox proportional hazards regression analysis in age- and multivariable-adjusted models.