https://orcid.org/0000-0002-5081-4809
Abstract
Inpatient zoledronic acid (IP-ZA) administered during the initial fracture hospitalization significantly improves the osteoporosis treatment rate. Clinical outcomes of IP-ZA after hip fracture remains uncertain. Here we report a new-user active comparator cohort study that emulated a randomized controlled trial using real-world data and evaluated the risk of death of any cause and radiologically confirmed subsequent new fractures among patients hospitalized for a hip fracture who had received IP-ZA as compared with propensity-matched controls who were not treated with anti-osteoporosis medication within the first-year post fracture. 654 patients who had received IP-ZA and 6877 controls (for whom antiosteoporosis treatment was indicated but no IP-ZA started during index hospitalization) were included in the study. The primary cohort comprised 652 IP-ZA patients (IP-ZA group) and 1926 matched controls (Untreated group) with 71.7% female, 92.1% White, and mean age of 80.9 years. Cumulative all-cause-mortality over the 24 months follow-up for the IP-ZA group was 12.3%, and 20.7% for Untreated group [hazard ratio (HR), 0.62; 95% confidence interval (CI), 0.49-0.78, p < 0.001)]. 585 (89.7%) patients in IP-ZA group received only a single dose of ZA during the 24 months, and the death rate of this single dose group was 13.3%, which was significantly lower than that of the Untreated group (HR, 0.70; 95% CI, 0.55-0.89, p = 0.003). Rates of radiologically confirmed cumulative subsequent new vertebral fractures were 2.0% in IP-ZA group and 5.4% in Untreated group (HR, 0.40; 95% CI, 0.22-0.71, P = 0.001). A similarly lower rate of new vertebral fractures was seen in the single dose subgroup (1.9% vs. 5.4%. HR, 0.44; 95% 0.24-0.82, p = 0.008). IP-ZA, administered during the initial hospitalization for hip fracture, was associated with lower all-cause-mortality and risk of radiologically confirmed subsequent new vertebral fractures, and thus offers a mechanism to narrow the treatment gap in patients having sustained a hip fragility fracture.
Lay Summary
Hip fracture is a serious complication of osteoporosis affecting approximately 300 000 Americans per year and is associated with a 20-30% one-year mortality rate. Most patients with hip fracture are elderly (average age 80-81 years), with multiple underlying medical conditions and are often unable to timely attend post-hospitalization outpatient follow-up to initiate anti-osteoporosis treatment. As a result, only ~10% of post-hip fracture patients receive treatment for underlying osteoporosis. We have previously reported that zoledronic acid (ZA) administered during initial fracture hospitalization (IP-ZA) is safe and can effectively improve the osteoporosis treatment rate to 70%. The present study analyzed the clinical outcomes of 652 patients who had sustained hip fractures and were treated with IP-ZA and 1926 matched controls and revealed significantly reduced rates of all-cause mortality and vertebral compression fracture (VCF) during a 2-year follow-up period. Of note, nearly 90% of the treated patients received only a single dose of ZA (namely, IP-ZA), suggesting that, for most patients, the only opportunity to receive anti-osteoporosis treatment was during the index fracture hospitalization. Importantly, reduced mortality and VCF rates were readily seen in this single-dose group of patients. Our data suggests that IP-ZA is beneficial for osteoporotic hip fracture.
Accepted manuscripts
