Abstract
Studies examining real-world effectiveness of osteoporosis therapies are beset by limitations due to confounding by indication. By evaluating longitudinal changes in fracture incidence, we demonstrated that osteoporosis therapies are effective in reducing fracture risk in real-world practice settings. INTRODUCTION: Osteoporosis therapies have been shown to reduce incidence of vertebral and non-vertebral fractures in placebo-controlled randomized clinical trials. However, information on the real-world effectiveness of these therapies is limited. METHODS: We examined fracture risk reduction in older, post-menopausal women treated with osteoporosis therapies. Using Medicare claims, we identified 1,278,296 women age ≥ 65 years treated with zoledronic acid, oral bisphosphonates, denosumab, teriparatide, or raloxifene. Fracture incidence rates before and after treatment initiation were described to understand patients' fracture risk profile, and fracture reduction effectiveness of each therapy was evaluated as a longitudinal change in incidence rates. RESULTS: Fracture incidence rates increased during the period leading up to treatment initiation and were highest in the 3-month period most proximal to treatment initiation. Fracture incidence rates following treatment initiation were significantly lower than before treatment initiation. Compared with the 12-month pre-index period, there were reductions in clinical vertebral fractures for denosumab (45%; 95% confidence interval [CI] 39-51%), zoledronic acid (50%; 95% CI 47-52%), oral bisphosphonates (24%; 95% CI 22-26%), and teriparatide (72%; 95% CI 69-75%) during the subsequent 12 months. Relative to the first 3 months after initiation, clinical vertebral fractures were reduced for denosumab (51%; 95% CI 42-59%), zoledronic acid (25%; 95% CI 17-32%), oral bisphosphonates (23%; 95% CI 20-26%), and teriparatide (64%; 95% CI 58-69%) during the subsequent 12 months. CONCLUSION: In summary, reductions in fracture incidence over time were observed in cohorts of patients treated with osteoporosis therapies.