Hormone replacement therapy in Norwegian women, 1996-1997

To assess the prevalence of hormone replacement therapy (HRT) among Norwegian women and examine factors related to use.

A random sample of 18,199 Norwegian women aged 45-64 years responded to a postal questionnaire in 1996-1997. The questionnaire included questions about menstruation status and fertility, oral contraceptives (OC) and HRT use, lifestyle, health and socio-economic status. The response rate was 60%.

Overall prevalence of ever using systemic or local HRT was 43.9%. Current use was reported by 31.9% of the women. The highest prevalence was in the age group of 55-59 years where 57.4% reported ever use, and 43.1% current use. Mean duration of use among current users was 4.6 years. More than 60% of the women were classified as postmenopausal, two-thirds of them naturally postmenopausal. The prevalence of ever using HRT was 51.8%. Prevalence of use was higher among earlier OC users, smokers, lean women and in households with high income. Among older women, users had a higher educational level than non-users, while this difference disappeared among the youngest of the women. Fixed combinations of estradiol and noretisteroneacetate either cyclic or continuous, are used by six out of ten users.

Our results confirm the increasing trend in sales of estrogens in Norway and suggest that user patterns are changing. More than four out of ten women aged 45-64 years reported ever use of HRT, and one out of three reported current use. Socio-economic differences between users and non-users seem to disappear among women under 55 years of age, but persist in the older age groups. Short time use still dominates.