Long Dosing Intervals of Parenteral Antiosteoporosis Medications and the Decrease in Societal Fracture Risk: An 11-Year Nationwide Population-Based Cohort Study

Objective: To evaluate the relationship between different dosing intervals of antiosteoporosis medications (AOMs) and the subsequent fracture risk among patients with newly initiated AOM therapies. Patients and Methods: In a nationwide population-based cohort study based on Taiwan's National Health Insurance Research Database, osteoporosis patients with 50 years of age or older who newly initiated AOM from January 1, 2008, to December 31, 2018 (n=336,229) were included. We categorized AOMs into short dosing intervals (oral AOMs) or long dosing intervals (parenteral AOMs). The adherence of treatment by medication possession ratio and subsequent fracture after treatment for 3 years were measured. Results: Among patients who initiated parenteral AOMs, the percentage of patients with high adherence (medication possession ratio ≥75%) increased from 33% in 2008 to 69% in 2018. However, among patients who initiated oral AOMs, the percentage of high adherence remained stable (30%) between 2008 and 2018. The use of parenteral AOMs increased from 1% in 2008 to 62% in 2018. At the same time, the percentage of high adherence of those initiated AOMs significantly increased from 34% in 2008 to 61% in 2018. The risk of subsequent fracture decreased significantly between 2008 and 2018 after controlling for all potential confounders (HR, 0.85; 95% CI, 0.81 to 0.89). Conclusion: AOMs with long dosing intervals not only increased adherence but also associated with the decrease in subsequent fracture risk at a nationwide scale.