The Impact of Nonhip Nonvertebral Fractures in Elderly Women and Men

Abstract

Nonhip nonvertebral fractures represent half of all osteoporotic fractures; however, their contribution to the burden of refracture and premature mortality is unclear. To examine the risk and burden of subsequent fracture and mortality associated with an initial nonhip nonvertebral fracture. This is a prospective cohort from the Dubbo Osteoporosis Epidemiology Study, 1989-2010 of community dwelling participants aged 60+ with incident fractures. Relative risk of all subsequent fractures and age-adjusted standardized mortality ratios were calculated according to initial fracture type. The total burden of adverse events was assessed using competing risk models with four potential outcomes: mortality after initial fracture, mortality after subsequent fracture, subsequent fracture and alive, or event-free. Of the 952 fractures in women and 343 in men, over half were nonhip nonvertebral fractures (486 in women and 173 in men). Nonhip nonvertebral fractures were associated with increased risk of any subsequent fracture (1.95 [1.67-2.27] for women and 2.47 [1.82-3.35] for men), hip refracture (2.11 [1.04-4.28] for women and 2.63 [1.35-5.13] for men), and vertebral refracture (1.89 [1.43-2.48] for women and 2.13 [1.20-3.79] for men). More importantly, nonhip nonvertebral fractures were associated overall with 20% excess mortality for the first 5 years postfracture, of which approximately half were due to initial fracture and the remaining due to subsequent fractures. Proximal fractures were associated with increased mortality risk per se, whereas distal fractures were associated with increased mortality risk only in the group who sustained subsequent fractures. Nonhip nonvertebral fractures are associated with significant risk of subsequent fracture including hip and vertebral refracture, and premature mortality. Due to their high prevalence, about half of all subsequent fractures and a quarter of all fracture-related excess mortality were attributable to nonhip nonvertebral fracture. Thus nonhip nonvertebral fracture warrants early investigation and appropriate intervention.