Objective: Publication of the Women's Health Initiative (WHI) study has changed our understanding on the effects of hormone replacement therapy. This study was designed to evaluate patterns of antiosteoporosis medication (AOM) use in a Medicaid population before and after the release of the WHI study results.
Methods: A descriptive time series analysis was conducted among women 50 years of age and older who were enrolled in the Pennsylvania Medicaid program from December 1, 2001, through December 31, 2002. All AOMs were identified, including estrogens, bisphosphonates, selective estrogen receptor modulators (SERMs), and calcitonin. The monthly prevalence of each AOM and drug class was estimated. Comparisons between pre-WHI (December 1, 2001–July 30, 2002) and post-WHI (August 1, 2002–December 31, 2002) study periods were made for overall AOM use by AOM drug class as well as by recipient characteristics.
Results: The overall prevalence of AOM did not change between pre-WHI and post-WHI study publication. However, there were significant changes in the prevalence of certain AOM drug classes. Estrogen use decreased significantly after the WHI study release for all age and racial groups. The prevalence for bisphosphonates and SERM increased significantly in the post-WHI period.
Conclusions: The WHI study influenced patterns of use of all types of AOM, decreasing estrogen and increasing nonestrogen use among postmenopausal women in a Medicaid program. These results suggest that the WHI study affected patterns of use of bone protective pharmacotherapy, with a shift in bone protection therapy use from estrogen to nonestrogen AOMs.
