Hip fracture rates declined in USA 1997–2006
MedWire News: Between 1997 and 2006, rates of hip fracture fell significantly among Californian adults of all ages, US researchers report.
They say the decline may be driven, at least in part, by the introduction of a state-wide "proactive bone health program."
The 10-year epidemiologic study was conducted within the Southern California region of Kaiser Permanente, a large integrated healthcare organization serving a racially, ethnically, and socioeconomically diverse population.
For each year between 1997 and 2006, the team calculated hip fracture rates, stratified by gender and age group (45-54, 55-64, 65-74, 75-84, and =85 years).
There were a total of 19,614 incident hip fractures during the study period among people aged 45 years and older. Nearly two-thirds of the fractures were in women.
In women, the overall incidence rate declined from 2.65 per 1000 person-years in 1997 to 2.24 per 1000 person-years in 2006, representing a 15.3% relative decline.
The greatest absolute change occurred in the oldest group of women, in whom the incidence dropped from 32.7 to 27.1 per 1000 person-years, whereas the greatest relative change was in women aged 45-54 years, in whom there was a 33.4% decline.
Men saw an identical overall decline in hip fracture rates, at 15.3% between 1997 and 2006, although absolute numbers were lower (falling from 1.52 to 1.29 per 1000 person-years).
Again, the greatest absolute change occurred among the oldest men, who saw a reduction from 21.0 to 18.3 per person-years over the study period, while the greatest relative change was in men aged 65-74 years, in whom there was a 31.8% decline.
The researchers compared the rates of decline in hip fracture incidence before (1997-2001) versus after (2002-2006) the introduction of a statewide bone health program. They found that the decline accelerated in the second period, falling by an additional 5.4% in women and 9.7% in men.
Writing in Osteoporosis International, Annette Adams (Kaiser Permanente Southern California) and team admit that secular trends in other factors may have contributed to the reduction in hip fractures over the study period.
For instance, life expectancy increased, possibly indicating improved overall health and better prevention and management of chronic conditions. In addition, obesity became more prevalent, and a higher body mass index has been associated with decreased fracture risk in women.
Nevertheless, they say the results "are consistent with a potential benefit of the active bone health intervention."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012
By Joanna Lyford