The prevalence of oestrogen replacement therapy in South Australia.

Objective: To ascertain the prevalence of the use of oestrogen replacement therapy in the South Australian community. DESIGN AND SETTING. Data was collected as part of the South Australian Health Omnibus Survey which involved a clustered, self-weighting, multi-stage, systematic representative area sample of 4608 households in metropolitan and country South Australia. One-thousand and forty-seven women over the age of 40 were personally interviewed by trained data collectors.

Outcome Measures: Demographic characteristics, prevalence of current or past oestrogen use, type of oestrogen used, period of use and reasons for using, stopping or never using therapy.

Results: Current use of oestrogen replacement therapy is 13.6% and ever use was 24.3%. The highest prevalence of use was in the age group 45-54 years. Use of oestrogen replacement therapy associated with women born in the UK or Ireland, middle income earners, intermediate education, recent visits to a general practitioner, a current relationship, previous hysterectomy and smoking. The commonest period of use for current users was 1-5 years and the longest 30 years. In contrast many past users had stopped within 6 months, usually because of side effects. The commonest reasons for oestrogen use were to alleviate symptoms, 'following hysterectomy' and to prevent osteoporosis. Only 4.3% took oestrogen to reduce the risk of heart attack or stroke. Reasons for not taking therapy were often due to the woman being premenopausal, having no symptoms or ignorance of the therapy.

Conclusion: Nearly one quarter of women over the age of 40 have used oestrogen replacement therapy. In general there is a perception only of the short term benefits amongst the current users and there is misinformation amongst the non-users. Therapy is often stopped after a very short time because of minor side effects.