Systemic Estrogen Use and Discontinuation After Alzheimer’s Disease Diagnosis in Finland 2005–2012: A Nationwide Exposure-Matched Cohort Study

BACKGROUND: It is unknown whether cognitive status or diagnosed cognitive decline affects estrogen use. OBJECTIVES: We assessed how common systemic estrogen use was among community-dwellers with Alzheimer’s disease (AD) and a matched comparison cohort without AD. METHODS: This study included an exposure-matched cohort of all Finnish community-dwelling women who received a clinically verified diagnosis of AD in 2005–2011 (N = 46,116; index cases) and an equally sized matched comparison cohort without AD. Follow-up began on the matching date (date of the AD diagnosis of the index case). Data on systemic estrogen use were obtained from the prescription register. Use initiation and discontinuation were assessed. RESULTS: Altogether 3.1% of women with AD and 4.3% of women without AD used estrogen during the follow-up period. Only < 0.5% initiated use during the follow-up period, but 3.7% continued use until death. The prevalence of estrogen use 1 year after the AD diagnosis declined in 2005–2011. CONCLUSIONS: There were no major differences in systemic estrogen use among Finnish women with AD when compared to those without AD. Although some persons initiated estrogen use after AD diagnosis and/or at an advanced age, the observed use patterns were mainly consistent with the current recommendations.