Comment on Cassell and Clapperton: A Decreasing Trend in Fall-Related Hip Fracture Incidence in Victoria, Australia

We read with interest the recent article by Cassell and Clapperton describing the decreasing trend in fall-related hip fracture rates among people aged 65 and older in Victoria, Australia from 1998/99 to 2008/09 [1].Over this time period, hip fracture rates decreased by 25 % among men and 23 % among women.Similar trends have been seen in other countries.We previously reported trends in hip fracture hospitalization rates among people aged 65 and older in the USA from 1990 to 2010 [2,3].Looking at the time period from 1998 to 2008, US rates declined by 22 % for men and 28 % for women-very similar to Cassell and Clapperton's results.Although the overall findings of this Australian study and our US studies are comparable, there are also some important differences.Cassell and Clapperton examined trends in hip fracture rates for men and women aged 65 and older separately and for both sexes combined by 5-year age groups, while we looked at trends in rates by 10-year age groups for men and women aged 65 and older separately.We found that most rates for men and women decreased significantly from 1996 to 2010, with the sharpest decline occurring among women aged 85 and older (annual percent change=-3.3;95 % confidence interval=-4.2 to -2.3).However, rates did not decrease significantly among men aged 65 to 74.Over the next two to three decades, these trends are likely to result in fewer hip fractures than Cassell and Clapperton's study might suggest.Underlying causes for these trends are unclear, but it does not appear to be a result of osteoporosis treatment with bisphosphonates, which is not widely used and often discontinued due to unpleasant side effects [4,5].Other