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

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.