Long-term effect of the Women's Health Initiative study on antiosteoporosis medication prescribing

Abstract

Aim: To describe long-term prescribing patterns of osteoporosis therapy before and after the Women's Health Initiative (WHI) publication.

Methods: We conducted a time-series analysis from 1997 to 2005 using nationally representative data based on office-based physician and hospital ambulatory clinic visits. Bivariate and multivariable analyses were conducted using chi-square tests and logistic regression, respectively, and trends in the prevalence of osteoporosis therapies were evaluated per 6-month (semiannual) intervals. Linear regression and graphic techniques were used to determine statistical differences in the prevalence trends between the two periods.

Results: Overall prevalence of therapeutic or preventive osteoporosis therapy was similar between the WHI periods. However, a significant decrease in estrogen therapy and increases in bisphosphonates, calcium/vitamin D were observed in the period after the WHI publication (p < 0.05). Multiple logistic regression analysis showed older age and white race were associated with a higher likelihood of antiosteoporosis medication (AOM) prescription, and Medicaid insurance type was associated with a lower likelihood of an AOM prescription. Excluding calcium/vitamin D, nonestrogen therapy was more likely to be prescribed in the after-WHI period (office-based physician clinic: [adjusted OR, aOR] 2.49 [2.04-4.04]; hospital-based clinic: aOR 2.42 [1.67-7.50]) Nonestrogen therapy was more prevalent in visits made by older women, women of white race, women with contraindicated conditions for estrogen therapy, and women from the Northeast region.

Conclusions: After the WHI publication, the overall prevalence of osteoporosis therapy did not change; however, a shift from estrogen to nonestrogen therapy was observed after the WHI publication. Black women were less likely to receive nonestrogen antiosteoporosis therapy in hospital-based clinics.

FIG. 1.

Semiannual changes in antiosteoporosis medication (AOM)-related visit prevalence in the office-based physician (Top) and hospital-based clinic (Bottom) settings. The denominator for each point estimate is the total number of patient visits within a 6-month interval. AOM, Antiosteoporosis medications include estrogens, bisphosphonates, calcitonin, selective estrogen receptor modulators (SERM), teriparatide hormone, calcium, and vitamin D that are prescribed, taken, or continued during a patient visit.