Prevalence and duration of postmenopausal hormone replacement therapy use in a managed care organization, 1990-1995.
OBJECTIVE
To determine the prevalence and duration of postmenopausal hormone replacement therapy (HRT) use and identify correlates of adherence to therapy.


METHODS
Population-based cohort study.


METHODS
Staff-model health maintenance organization.


METHODS
Female members, 40 years and older.


RESULTS
Prevalence and duration of use were measured between 1990 and 1995. Duration was assessed by Kaplan-Meier and proportional hazards methods. Hormone replacement therapy use increased from 10.3% in 1990 to 20.7% in 1995. Greatest use (24%) occurred among menopausal women age 50 to 54 years. Less than 5% of women 75 and older used HRT. Among 1,680 first-time recipients of HRT, two thirds of initial prescriptions were written by internists. Thirty-eight percent discontinued HRT within 1 year. For the subset whose indication for therapy was ascertained, prevention of chronic disease was associated with a 33% 1-year discontinuation rate. Factors associated with longer duration of therapy included white race (relative risk [RR], 1.63; 95% confidence interval [95% CI], 1.32 to 2.02), younger age (RR, 1.02 per year; 95% CI 1.01 to 1.03), and changing the preparation or dose of estrogen (RR, 5.62; 95% CI, 4.33 to 7.25). The formulation (esterified estrogens 0.625 mg versus conjugated estrogens 0.625 mg) was also associated with greater duration of use; all other estrogens were, as a group, associated with shorter duration of use. Those who received their initial HRT prescription from an internist were more likely to continue therapy than those who received it from a gynecologist.


CONCLUSIONS
Despite increased use of HRT, only a minority of women in this population used HRT, and many of those discontinued therapy within 1 year.
Department of Ambulatory Care and Prevention, Harvard Medical School and Harvard Pilgrim Health Care, Boston, Massachusetts, USA. maureen_connelly@hphc.org
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Connelly
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Richardson
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Platt
D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D015914:Estrogen Replacement Therapy / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008329:Managed Care Programs / Q000706:statistics & numerical data*; D008404:Massachusetts; D008485:Medical Audit; D008875:Middle Aged; D010819:Physician's Role; D015995:Prevalence; D011897:Random Allocation; D013997:Time Factors; D044465:White People