Role of Side Effects, Physician Involvement, and Patient Perception in Non-Adherence with Oral Bisphosphonates.

Introduction: The benefits of osteoporosis therapy are compromised by low adherence, thus requiring a better understanding of its barriers and unmet needs. The objective of this study was to assess reasons for non-adherence with oral bisphosphonates among osteoporotic women.

Methods: A cross-sectional patient survey of women who initiated therapy with risedronate or alendronate between the years 2010 and 2012 were non-adherent [Medication Possession Ratio (MPR) <70%] or switched therapy within the first year. Survey participants were identified using Maccabi Health Services computerized database. Patients who gave informed consent completed a 20-min telephonic survey, assessing reasons for discontinuation or switching, including physician involvement, side effects, administration regimen, perceptions of bone health, and medications' efficacy.

Results: The study population included 493 females (mean age = 66 ± 7) of whom 40% discontinued all anti-osteoporotic therapy (mean MPR = 19%), 9% remained on initial therapy (mean MPR = 47%), and 51% switched therapy (mean MPR = 62%). Family history, fracture history, socioeconomic status, and index drug class and frequency were similar in all groups. The most common reasons for switching or discontinuation of the first-line therapy were gastrointestinal side effects, such as heartburn, acid reflux or other (40.0%), and physician recommendation (26.7%). The major reasons for complete discontinuation of therapy were side effects (26.9%) and physician recommendation (20.0%). Perceived low importance was more commonly mentioned than high cost of medication (14% vs. 3%).

Conclusion: Our findings highlight the importance of low tolerability to non-adherence with osteoporosis therapy and underlines poor patients' awareness and sub-optimal physicians' involvement in conveying the importance of this therapy.

Funding: Merck & Co Inc.