Cohort Profile: The Danish nurse cohort

Abstract

From the 1970s to the mid-1990s, ∼20–30% of Danish women between 55 and 65 years of age used hormone replacement therapy (HRT).^1,2 It was primarily used to alleviate climacteric symptoms, but from 1980s the therapy was also used for prevention of osteoporosis and from the 1990s for prevention of cardiovascular diseases. The literature based on observational studies, primarily US studies, suggested a considerable risk reduction of osteoporotic fractures³ and coronary heart disease, whereas findings on the effect of HRT on breast cancer were inconsistent.⁴