CALCIUM, ESTROGEN, AND PROGESTIN IN THE TREATMENT OF OSTEOPOROSIS

Self-reported calcium use in a cohort of postmenopausal women receiving osteoporosis therapy: results from POSSIBLE US™

Calcium use was common and remained high among women on osteoporosis therapy. Use of calcium-supplemented pharmacologic therapy increased from 65.1 to 76.0% in these women (mean follow-up, 27.5 months). Over 12 months, calcium discontinuation was fairly similar among women using calcium only (23.7%) and women supplementing pharmacologic therapy with calcium (22.5%).

INTRODUCTION

Calcium has an important role in bone health. This study describes calcium use and persistence in a postmenopausal osteoporosis treatment cohort.

METHODS

Subject-reported calcium use was analyzed for 3,722 participants of the Prospective Observational Scientific Study Investigating Bone Loss Experience (POSSIBLE US(TM)) who used calcium either as their sole osteoporosis treatment (calcium only) or to supplement pharmacologic osteoporosis therapy (supplementers). Descriptive analyses were conducted. Kaplan-Meier methods were used to estimate the probability of discontinuing calcium therapy, and logistic regression was used to assess associations (age-adjusted odds ratios) between healthy behaviors and calcium use.

RESULTS

At entry, there were 711 calcium-only subjects and 1,960 of 3,011 subjects on pharmacologic osteoporosis therapy also supplementing with calcium (supplementers). The percentage of supplementers increased from 65.1 to 76.0% during follow-up (mean, 27.5 months). During the first 12 months on study, the probability of calcium discontinuation was 23.7% (95 % confidence interval [CI], 20.7 - 27.0) among calcium-only subjects and 22.5% (95% CI, 20.7-24.5) among supplementers. Supplementers who discontinued pharmacologic therapy were more likely to discontinue calcium than supplementers who continued pharmacologic therapy (34.9 versus 14.8%). Overall 54.2% of calcium-only subjects who discontinued calcium and 42.3% of supplementers who discontinued calcium resumed calcium use during follow-up. Regular exercise was positively correlated with calcium use at study entry.

CONCLUSIONS

Calcium supplementation in pharmacologically treated subjects increased over time. Persistence with calcium was high. Discontinuation of pharmacologic osteoporosis therapy was associated with an increased likelihood of discontinuing calcium use.

Women's use of hormone therapy before and after the Women's Health Initiative: a psychosocial model of stability and change

OBJECTIVE

This longitudinal study examined factors underlying hormone therapy (HT) use before and after termination of the landmark Women's Health Initiative (WHI) estrogen plus progestin HT trial in July 2002, after which dramatic reductions in HT use occurred.

METHODS

A community sample of 324 women (aged 40-86) from Arizona was interviewed four times between 1995 and 2003. A model of medical and psychological factors underlying intentions for long-term HT use expressed in 1995/1996 was developed and employed to predict subsequent use and discontinued use pre- and post-WHI.

RESULTS

Philosophy of menopause and perceived susceptibility to breast cancer predicted perceived benefits of and barriers to long-term HT use, beyond age, oophorectomy, and physician recommendation. Age, benefits, and barriers predicted intentions for long-term HT use over and above current use. Intentions predicted use 3 years later, controlling for previous use. HT use in 1995/1996 predicted use until the WHI announcement, but not thereafter. Oophorectomy predicted continued HT use before WHI trial termination; perceived barriers, expressed 8 years earlier, predicted discontinued use after WHI trial termination.

CONCLUSIONS

Medical and psychological factors predicted sustained and discontinued HT use before and after the WHI announcement. The WHI findings apparently activated potential barriers to use expressed almost a decade earlier.