Practice and patterns of estrogen treatment in climacteric women in a Swedish population. A descriptive epidemiological study. Part I.

A cohort of 23 233 women to whom estrogens had been prescribed and constituting a total material from a defined Swedish population was recruited for the purpose of conducting a prospective follow-up study of endometrial cancer. Their exposure to estrogens was studied in detail by means of a comprehensive questionnaire, which was mailed to 735 randomly selected women from the cohort and answered by 89%. This paper describes the practice of estrogen prescribing in the population and the patterns of exposure of the cohort, as estimated from the sample. Our results indicated: restrictive usage of estrogens with a marked downward secular trend in the frequency of prescriptions; short duration of treatment and frequent temporary interruptions; predominant choice of estradiol valerate compounds; preference for cyclic administration and low-strength tablets; acceptance of recommended dose levels; and adherence to a few, established indications for treatment. When compared with data from a large number of other epidemiological studies, the risk of endometrial cancer in this cohort is likely to be lower.