Compliance and persistence with oral bisphosphonates for the treatment of osteoporosis in female patients with rheumatoid arthritis

Background: Poor adherence with oral bisphosphonates (BPs) can mitigate their therapeutic benefit for osteoporosis and is a significant clinical burden. Most previous studies regarding adherence with oral BPs have focused on postmenopausal osteoporosis, but little attention has been given to patients with rheumatoid arthritis (RA). Thus, we investigated compliance and persistence with oral BPs in the treatment of osteoporosis and analyzed risk factors for poor adherence in female patients with (RA) in real setting. Methods: This is a retrospective longitudinal study including 396 female patients with RA in whom oral BPs were newly initiated from Aug 2004 to Aug 2014 at a university rheumatology center in South Korea. Compliance was quantified using the 1-year medication possession ratio (MPR), while persistence was defined as duration from the initiation to the end of BPs therapy without interruption exceeding 56 days. Seropositve RA was defined as having a positive test result for the presence of either rheumatoid factor or anti-cyclic citrullinated peptide antibody. Results: Of 396 RA patients, 221 (55.8%) were prescribed risedronate 35 mg weekly; 17 (4.3%) received alendronate 70 mg weekly; and 158 (39.9%) received ibandronate 150 mg monthly. The 1-year MPR was 70.1% and the proportion of RA patients with the 1-year MPR = 0.8 was 60.1%. A total of 274 (69.2%) patients discontinued oral BPs during the study period and persistence with BPs was 63.3% at 1 year, 50.7% at 2 years and 33.3% at 3 years. The most common cause of non-persistence was adverse events (47.5%), followed by poor health literacy (40.5%) and cost (12%). Both compliance and persistence with monthly oral BPs were significantly lower than those with weekly regimens (OR: 2.48, 95% CI: 1.59-3. 89, P < 0.001 and HR: 2.19, 95% CI: 1.69-2.83, P < 0.001, respectively). Additionally, patients with seropositive RA showed better compliance and persistence with BPs compared with their seronegative counterparts. Conclusions: Compliance and persistence with oral BPs in RA patients were suboptimal in real practice, thereby limiting the efficacy of osteoporosis treatment. Extending the dosing interval of BPs may improve medication adherence in RA patients.