Hormone replacement therapy in Denmark, 1995-2004.

BACKGROUND

Recently, the Danish National Register of Medicinal Product Statistics (NRM) was opened for research purposes, and therefore, on an individual basis, can merge with other national registers. The aim of this study was to analyse the use of hormones based on the individual data of the entire Danish female population, with the focus on a detailed evaluation of specific hormone regimens and factors associated with systemic hormone replacement therapy (HRT).

METHODS

All Danish female citizens, aged 15-70 years during the study period 1995-2004, were identified in the Civil Registration System, and their redeemed prescriptions for hormones and medication for diabetes, hypertension, hypercholesterolemia and heart conditions were retrieved from the NRM. Information on habitation, education, employment and gynaecological surgery was obtained from other national registers.

RESULTS

After 2002, the use of HRT was reduced by 65%. In 2002, HRT was most prevalent in women aged 55-59 years, when an average of 200 defined daily doses per 1,000 women per day was recorded. In 2002, approximately 39% of women aged 50-57 years were ever exposed to HRT. The mean duration of HRT was 5 years in an 8-year time window. During the study period, there was a significant decline in the use of systemic hormones, initially due to a decrease in cyclic combined therapy, but after 2002 continuous combined therapy decreased rapidly. HRT was positively associated with middle-term education, employment status, and living in urban areas. Women treated for diabetes used hormones less frequently than women without diabetes. Women using antiarrhythmics or antihypertensives used hormones more often than women not using this medication. HRT was positively associated with gynaecological surgery.

CONCLUSION

One in five women, aged 50-59 years, redeemed daily HRT. Use of HRT declined from 1995 to 2002, but more than halved after 2002. HRT is associated to redemption of other medications of significance for health.