Zoledronic acid for hip fracture during initial hospitalization
WuQiang Fan, Xiaoxu Sun, Benjamin Z. Leder, Hang Lee, Thuan V. Ly, Charles T. Pu, Esteban Franco‐Garcia, Marcy B. Bolster
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 remain uncertain. Here we report a cohort study that emulated a randomized controlled trial using real-world data and evaluated the risk of all-cause-mortality and radiologically confirmed subsequent new fractures among patients hospitalized for a hip fracture who had received IP-ZA as compared with propensity-matched controls. A total of 654 patients who had received IP-ZA and 6877 controls (for whom anti-osteoporosis 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 participants, with a mean age of 80.9 years. Cumulative all-cause mortality over the 24-month follow-up for the IP-ZA group was 12.3% and 20.7% for the untreated group (hazard ratio [HR], 0.62; 95% CI, 0.49-0.78, p < .001). A total of 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 = .003). Rates of radiologically confirmed cumulative subsequent new vertebral fractures were 2.0% in the IP-ZA group and 5.4% in the untreated group (HR, 0.40; 95% CI, 0.22-0.71, p = .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 = .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.