Gastrointestinal Side Effects in Postmenopausal Women Using Osteoporosis Therapy: 1-year Findings in the POSSIBLE US Study

Objective: To characterize gastrointestinal side effects (GI SEs) and its associations with medication discontinuation, health-related quality of life (HRQoL), and treatment) satisfaction in postmenopausal women prescribed osteoporosis (OP) therapies.

Methods: Prospective Observational Scientific Study Investigating Bone Loss Experience (POSSIBLE US*) participants enrolled October 27, 2004 - January 25, 2007 and complete questionnaires for up to 3 years. GI SEs for women new to or stable on therapy at entry were characterized at 6 and 12 months. Adjusted odds of experiencing GI SEs; mean HRQoL and treatment satisfaction scores; and risk of discontinuing therapy for bisphosphonate (BP) versus non-BP users were compared with logistic and generalized linear models.

Results: About 20% of women reported >or=1 GI SE at entry. GI SEs at month 6 were more common in BP than non-BP users (new: OR = 1.5, 95% CI: 1.2-2.0; stable: OR = 1.7, 95% CI: 1.3-2.1). Women new to OP therapy with GI SEs at month 6 had lower LS Mean HRQoL (OPAQ-SV Emotional Status: 72.3 vs. 78.2, p = 0.005) and treatment satisfaction scores (SEs: 71.4 vs. 82.9;

Efficacy: 58.6 vs. 65.6; Global: 55.0 vs. 64.4; all p <or= 0.02) than those without GI SEs. Women reporting any GI SE had higher therapy discontinuation than those without GI SEs (6-month OR = 1.39, 95% CI: 1.05-1.84; 12-month OR = 1.30, 95% CI: 1.03-1.63; both p <or= 0.03).

Conclusion: GI SEs were common among women on OP therapy, were more common in BP than non-BP users, and were associated with increased therapy discontinuation. Lower HRQoL and treatment satisfaction associated with GI SEs may influence medication discontinuation.