Declining hip fracture rates in the United States

Abstract
SIR—Unintentional falls are a common occurrence among older adults, affecting ~30% of persons aged 65 years and older annually [1]. One of the most serious fall outcomes is hip fracture, an injury that often results in long-term functional impairment, nursing home admission and increased mortality [2]. More than 90% of hip fractures are caused by falls [3], usually by falling onto the hip [4]. In 2006 there were ~293,000 hospital admissions for hip fracture [5]. Osteoporosis, a metabolic disease characterised by low bone mineral density (BMD) and bone structure deterioration, greatly increases the chances that a person who falls will sustain a hip fracture [6]. The National Osteoporosis Foundation estimates that more than 10 million people over age 50 in the United States have osteoporosis and another 34 million have low BMD and are at risk for the disease [7].