Utilisation of hormone replacement therapy in the United Kingdom. A descriptive study using the general practice research database.

OBJECTIVE: To determine prevalence and patterns of hormone replacement therapy (HRT) utilisation in women in the UK. DESIGN: Prospective observational study. SETTING: UK general practice. POPULATION: Women from general practices throughout the UK. METHODS: The study period was 1 January 1992 to 31 December 1998. Age-specific prevalence was calculated for each year. Trends in prescribing patterns were described over time. A sub-cohort of 'new starters' on HRT was identified to establish patterns of use, including duration of use and switching of preparations. Characteristics of the sub-cohort were compared with a reference group of non-HRT users. MAIN OUTCOME MEASURES: Prevalence, prescribing patterns and differences in characteristics between HRT users and non-HRT users. RESULTS: Among women aged 45-64, prevalence of HRT use increased from 18.6% in 1992 to 27.7% in 1998. Secular trends were observed away from prescribing combined-sequential preparations and towards use of combined-continuous preparations. Among the prescriptions for combined HRT products, only 4.3% contained medroxyprogesterone acetate (MPA). A total of 45.7% of women without a record of a hysterectomy and 53.8% of women with a record of a hysterectomy used HRT for at least three years. When women were partitioned by year of starting HRT, there was a trend of increasing duration of use across the seven years. Some women without a record of a hysterectomy were receiving unopposed oestrogen without progestogen supplementation. CONCLUSIONS: Within the past decade, use of HRT has increased among women in the UK with large numbers of women using HRT for long periods and treatment often tailored to the individual.