Low use of long-term hormone replacement therapy in Denmark

To examine individual use of hormone replacement therapy (HRT) in a defined population of Danish women during a 5-year period. HRT may reduce osteoporosis and cardiovascular disease in postmenopausal women, but may also have side-effects. Little is known about the use of HRT in most populations.

A Pharmacoepidemiological Prescription Database was used to identify all reimbursed prescriptions for HRT in the county during the period 1991 to 1995. The Danish retail pharmacies' drug subsidy system made it possible to identify prescriptions by individual use.

We examined 255797 HRT prescriptions issued during the period in the County of North Jutland. Total sales reached 16.5 million defined daily doses (DDDs), purchased by 31653 women, which corresponds to 26.9% of the female population above the age of 39 years. The annual prevalence proportion of current users rose from 10.4% to 14.8% during the study period, and the therapeutic intensity (DDD/1000 women/day) increased from 20.6 to 32.0. The mean DDD sum of systemic HRT per user was 73.4 in 1991; it and the proportion of users who received less than 90 DDD per year (83.4% in 1991) remained almost constant during the study period. The amount of oestrogen unopposed by progestin was high, 28.1% of all prescriptions.

Less than one-fifth of the study population used HRT for more than 3 months per year, and only 32.8% of the women who were new users of HRT in 1992 continued this therapy throughout the study period.