Prevalence of estrogen or estrogen-progestin hormone therapy use

To use nationally representative data to produce prevalence estimates of combination estrogen-progestin therapy and estrogen-only therapy by covariates, and to evaluate differences between current use of short duration (less than 5 years) and current long-term use.

We analyzed data from female respondents 40 years of age and older (n = 9400) who were interviewed in the 1999 National Health Interview Survey. Hormone therapy use was categorized into four types: current estrogen-progestin therapy use, current estrogen-only therapy use, former hormone therapy use, and never use. We calculated the prevalence of hormone therapy by different levels of previously identified covariates of hormone therapy, as well as overall prevalence of hormone therapy use by length of use.

Approximately 24% of women aged 40 years or older were current hormone users. Of these, 30% were taking estrogen-progestin therapy, and 70% were taking estrogen-only therapy. The prevalence of hormone use differed dramatically by hysterectomy status and age, and less so by many demographic, health-risk behavior, medical access, and medical history variables. Among women with no hysterectomy, the associations with many of the covariates were stronger for estrogen-progestin therapy use than for estrogen-only therapy use. Only 3% of women were estimated to be current estrogen-progestin therapy users for 5 or more years, whereas 10% were current estrogen-only therapy users for 5 or more years.

Although many women at midlife and older were current hormone users, very few were long-term users of estrogen-progestin therapy.