Use of hormone replacement therapy in the Hong Kong public health sector after the Women's Health Initiative trial

OBJECTIVES

To determine the impact of Women Health Initiative (WHI) trial on the use of hormone replacement therapy (HRT) in the Hong Kong public health sector.

METHODS

The central prescription database of the Hospital Authority was used to describe the half-yearly trend in the use of HRT between July 2000 and December 2003. The data of hysterectomy was retrieved from another clinical database.

RESULTS

Before the publication of the WHI trial in July 2002, conjugated equine estrogens (CEE) and its related products dominated HRT prescribing. Relative to the first half of 2002, there was an immediate and substantial decline by 43.5% in the prescriptions of combined CEE/progestogen products and a modest decline by 22.4% in the prescriptions of CEE-alone therapy in the second half of 2002. In the first half of 2003, a decline in the prescriptions of all HRT preparations except raloxifene was observed. However, in the second half of 2003, there were no more declines in overall HRT users. Relative to the first half of 2002, the decline in the overall HRT users in the first half of 2003 was more than 46% in women aged 50-69. The decline was greater in women with a history of hysterectomy (60.3%) than women without (38.6%), but was similar between gynaecology specialty (41.7%) and non-gynaecology specialty (43.9%).

CONCLUSIONS

Similar to the U.S., an immediate and substantial decline in the use of CEE and its related products was observed in Hong Kong after the publication of the WHI trial.

Continuation rate of hormone replacement therapy in Hong Kong public health sector

OBJECTIVES

To assess the 1-year continuation rate of HRT prescribed in Hong Kong public health sector and to identify factors affecting this continuation rate.

METHODS

All women who received at least one dispensed prescription of estrogens between January 1998 and December 2000 from 36 specialist outpatient clinics of the Hospital Authority were selected, and observed for at least 2 years and at most 3 years. The duration of use and variables including age, types of hormones, routes of delivery, dose of estrogen, and prescribing specialty were retrieved from the central prescription database of the Hospital Authority.

RESULTS

Of 12,711 incident users of HRT, more than half were aged 50-59. Most (78.5%) of the users took conjugated equine estrogens (CEE) 0.625 mg or related products. Only a small proportion (3.0%) of women used CEE 0.3 mg. Initial estrogen prescriptions were written by gynaecologists in 86.7%. The overall 1-year continuation rate was 68.3%. The highest and lowest continuation rates were observed in women aged 40-49 and the two extreme age groups (35-39 and 70-79), respectively. Better continuation rate was observed in women taking estrogen-only therapy such as CEE or estradiol (overall 76.3%) than in women using continuous combined therapy (58.6%), sequential combined therapy (64.8%), or transdermal estrogen (60.6%). In the age group 60-69, the use of CEE 0.3 mg was associated with better continuation rate than CEE 0.625 mg.

CONCLUSIONS

Better continuation rate at 1 year was associated with age younger than 60, oral route of HRT and hysterectomy.