Persistence and switching patterns among women with varied osteoporosis medication histories: 12-month results from POSSIBLE US

During the first year of Prospective Observational Scientific Study Investigating Bone Loss Experience (POSSIBE US), many women transitioned (i.e., discontinued or switched) from their baseline osteoporosis medication. Participants not on stable therapy at entry, with side effects, and with poor physical status were at higher risk of transitioning. Understanding factors associated with persistence may lead to improved outcomes.

Postmenopausal osteoporosis (PMO) medication use patterns may differ by treatment history and drug class. We describe these patterns among patients in primary care settings using patient-reported data.

Data from 3,006 participants of the POSSIBLE US were used to estimate the probability of a baseline PMO medication transition (i.e., discontinuation or switch) and hazard ratios (HRs) for predictors of these transitions.

One year after study entry, the probability of persisting with a baseline medication was 66% (95% CI: 64-68%). After adjusting for age and osteoporosis diagnosis, factors at entry independently associated with a higher risk of baseline medication transition were treatment status cohort, side effect severity, and OPAQ-SV physical function score. Compared to participants stable on therapy at entry, others had a higher risk, ranging from HR = 1.59 (95% CI: 1.36-1.85) for those new to therapy to HR = 2.00 (95% CI: 1.27-3.15) for those who recently augmented therapy at entry. Participants reporting moderate (HR = 1.31, 95% CI: 1.09-1.57) or severe (HR = 1.88, 95% CI: 1.49-2.39) side effects had a higher risk than those not reporting side effects. Participants reporting Osteoporosis Assessment Questionnaire-Short Version physical function scores in the lowest tertile had a higher risk (HR = 1.27, 95% CI: 1.07-1.52) than those reporting scores in the highest tertile.

Baseline osteoporosis medication transitions were common in the first year of POSSIBLE US. Participants not on stable therapy at entry, or who reported severe side effects, or had poor physical health status were at higher risk for these transitions.