Oral bisphosphonates are associated with reduced mortality after hip fracture

Abstract

Intravenous bisphosphonates reduce mortality following hip fracture. We determined whether new use of oral bisphosphonates was also associated with reductions in mortality in 209 hip fracture patients. Oral bisphosphonate exposure led to relative reduction of 8% per month of use (p = 0.001) or about a 60% reduction in mortality per year of use. Intravenous bisphosphonates reduce mortality following hip fracture. Using prospectively collected long-term data from a randomized trial of osteoporosis quality improvement for hip fracture, we determined whether new use of oral bisphosphonates was associated with reductions in mortality or the composite outcome of death or new fracture. Originally, 220 hip fracture patients were randomized to case manager (n = 110) or usual care followed by facilitated bone mineral density (BMD) testing (n = 110) interventions. All were eligible for bisphosphonate treatment. Post-randomization, we followed patients for 3 years and ascertained bisphosphonate treatment, medication adherence and persistence, all-cause mortality, and new clinical fractures. Proportional hazards analyses with time-varying treatment status were undertaken. The final study cohort included 209 patients: 136 (65%) females, 104 (50%) older than 75 years, 90 (43%) with poor self-reported health, and 38 (18%) underweight. Of these, 76 (36%) had a previous fracture before hip fracture and 132 (81%) had low BMD. A total of 101 (46%) patients started oral bisphosphonates and 65 (64%) remained on treatment at the final evaluation. Overall, 24 (11%) patients died, 19 (9%) had new fractures, and 42 (20%) reached the composite outcome of death or fracture. Compared to no treatment, bisphosphonate exposure was independently associated with reduced mortality (17[16%] vs. 7[7%]; adjusted hazard ratio (aHR) = 0.92 per month treated; 95%CI, 0.88-0.97) and composite endpoints (28[26%] vs. 5[15%]; aHR = 0.94 per month treated; 95%CI, 0.91-0.97). Like intravenous bisphosphonates after hip fracture, our study suggests that oral bisphosphonates may be associated with reductions in all-cause mortality.