Systematic review of adherence to bisphosphonates for the treatment of osteoporosis finds suboptimal levels of persistence and compliance. Poor bisphosphonate compliance increases fracture risk.
Introduction: The objectives of the study were to measure the persistence and compliance with bisphosphonates for the treatment of osteoporotic patients, and to estimate the influence of compliance on fracture risk.
Methods: A systematic review of bisphosphonate adherence in clinical practise provided new evidence to perform a meta-analysis of the means of bisphosphonate persistence and compliance, with a subsequent meta-analysis of fracture risk comparing poorly versus highly compliant patients.
Results: Fifteen articles, totalling 704,134 patients, met our inclusion criteria. Most of the patients were postmenopausal women treated with bisphosphonates. The 3.95% of the patients received hormone replacement therapy, but the rest received bisphosphonates. The meta-analysis of five articles totalling 236,540 patients, who were followed for 1 year, provided a pooled persistence mean of 184.09 days. The meta-analysis of five articles, totalling 234,737 patients, who were also followed for 1 year, provided a pooled medication possession ratio mean of 66.93%. The meta-analysis of six articles, totalling 171,063 patients, who were followed for varying periods of time between 1 and 2.5 years, provided a pooled 46% increased fracture risk in non-compliant patients versus compliant patients. The increased fracture risk was lower for non-vertebral (16%) and hip (28%) than for clinical vertebral fractures (43%).
Conclusions: Persistence and compliance are suboptimal for postmenopausal women undergoing bisphosphonate therapy for osteoporosis. The clinical consequence of this low compliance is an increased risk of fracture, which is lower for non-vertebral than for clinical vertebral fractures.