Hormone replacement therapy: I. A pharmacoeconomic appraisal of its therapeutic use in menopausal symptoms and urogenital estrogen deficiency.

Menopause and the accompanying reduction in estrogen production may cause a number of symptoms in women which include hot flushes, sweating, mood and sleep disturbances, fatigue and urogenital dysfunction. The effectiveness of estrogen-based hormone replacement therapy (HRT) in ameliorating these symptoms, and in preventing long term sequelae such as osteoporosis, is well established. Comparative trials indicate that oral conjugated estrogens 0.625mg, oral ethinyl estradiol 0.02mg and transdermal estradiol 0.05mg have equivalent efficacy in relief of mild to moderate menopausal symptoms and prevention of bone mineral loss. Concomitant progestogen therapy is usually prescribed for women with intact uteri to protect against endometrial hyperplasia and carcinoma. The addition of progestogen maintains and may even enhance the bone-conserving effects of estrogen, and continuous regimens appear to reduce the incidence of irregular menses. Adverse reactions are predominantly local skin irritation with transdermal preparations (14% of patients) and systemic effects common to most forms of HRT including breast tenderness, flushing, headache and irregular bleeding, occurring in less than or equal to 2% of patients. Data concerning the effect of HRT on quality of life are limited, but most analyses have assigned utility values of 0.99 for mild and 0.95 for severe menopausal symptoms. However, recent clinical data suggest that these utility values may underestimate the impact of menopausal symptoms on quality of life. The cost benefit and cost effectiveness of HRT in the treatment of menopausal symptoms have not been fully researched, although preliminary results suggest that conjugated estrogens and transdermal estradiol compare well with alternative therapies such as veralipride and Chinese medicines. A Swedish study using a prevalence-based approach estimated that estriol treatment in all women with urinary incontinence aged greater than or equal to 65 years resulted in monetary savings compared with treating 20% of women. Cost-utility data indicated that the change in quality-adjusted life years (QALYs) with HRT was always positive, but the degree of change was determined by the baseline assumptions. Estimated changes in QALYs with HRT ranged from 0.006 for 5 years of treatment with unopposed estrogen in women with intact uteri, to 0.5 for 10 years of the same treatment in women with severe menopausal symptoms following hysterectomy. Compliance with HRT is suboptimal as 5 to 50% of women withdraw from therapy, thereby increasing costs per year of life saved.(ABSTRACT TRUNCATED AT 400 WORDS)