Anti-fracture treatment efficacy by age

Abstract

There is a common belief that antiosteoporosis medications are less effective in older adults. This study used data from randomized controlled trials (RCTs) to determine whether the anti-fracture efficacy of treatments and their effects on bone mineral density (BMD) differ in people ≥70 compared to those <70 years. We used individual patient data from 23 RCTs of osteoporosis medications collected as part of the FNIH-ASBMR SABRE project. We assessed the following fractures: radiographic vertebral, non-vertebral, hip, all clinical and all fractures. We used Cox proportional hazard regression to estimate treatment effect for clinical fracture outcomes, logistic regression for the radiographic vertebral fracture outcome and linear regression to estimate treatment effect on 24-month change in hip and spine BMD in each age subgroup. The analysis included 123,164 (99% female) participants; 43% being ≥ 70 years. Treatment with anti-osteoporosis drugs significantly and similarly reduced fractures in both subgroups [e.g. OR = 0.47 and 0.51 for vertebral fractures in those below and above 70 years, interaction p = 0.19; HR for all fractures: 0.72 vs 0.70, interaction p = 0.20)]. Results were similar when limited to bisphosphonate trials with the exception of hip fracture risk reduction which was somewhat greater in those <70 (HR = 0.44) vs ≥70 (HR = 0.79) years (interaction p = 0.02). Allocation to anti-osteoporotic drugs resulted in significantly greater increases in hip and spine BMD at 24 months in those >70 compared to those <70 years. In summary, anti-osteoporotic medications similarly reduced the risk of fractures regardless of age and the few small differences in fracture risk reduction by age were of uncertain clinical significance.