Monday, December 3, 2007
The researchers list 11 risk factors for hip fractures.
SACRAMENTO, Calif. — A new computer tool developed by a University of California, Davis, doctor can help predict — and may help prevent — potentially deadly hip fractures in women.
Internist John Robbins hopes the computer program can guide physicians in their efforts to protect vulnerable patients from fractures that too often lead to disability or death. Robbins’ research appeared in last month’s edition of the Journal of the American Medical Association.
Robbins cautioned that his computerized algorithm is not foolproof, and that it needs to be tested further. But Robbins said he believes the modeling can help women get a more personalized indication of their risk.
Analyzing data collected from the nationwide Women’s Health Initiative, Robbins and other researchers identified 11 risk factors for hip fractures among postmenopausal women. They go beyond age and weight and include things such as steroid drug use, smoking and ethnic background.
Researchers then developed a model that can quickly evaluate an individual’s risk of suffering a hip fracture within five years. The model has been adapted for public use via the Internet.
Currently in the United States, there are an estimated 329,000 hip fractures per year, many of them resulting in long-term hospitalization and disability or causing complications that lead to death.
To predict a person’s risk and to determine whether bone-protecting medicines might help prevent a fracture, doctors have relied on a bone mineral density imaging technique called a dual-energy X-ray absorptiometry scan.
The scan is most often used to diagnose osteoporosis, a bone-weakening disease that typically afflicts women. The lower the density of the bone, the greater the risk of fractures.
Although bone density scans are good at predicting future fractures, Robbins said they are costly and not always available to those who might benefit from them. He added that most hip fractures occur in women whose bone density scans are negative for osteoporosis.
Robbins’ tool instead relies on factors other than bone mineral density associated with a higher risk of hip fracture. Taken together, they can further refine the predicted risk of future fractures.
Race, for example, can play a role in fracture risk but must be weighed against other risk factors, said Robbins.
For example, black women generIn addition to race, prior fractures after age 54 and family history of fractures, other variables used in Robbins’ model are weight, long-term use of corticosteroid drugs (which can weaken bone), level of physical activity, cigarette smoking and diabetes.
For Ginger DeGregory, who participated in the Women’s Health Initiative, Robbins’ model has already provided some peace of mind.
The 64-year-old considers herself very healthy, but worries about brittle bones. And because both her parents died in their 40s, she doesn’t know whether she has a genetic predisposition to osteoporosis.
“We have a cabin in the mountains, and we take our grandchildren there to play in the snow,” she said. “I keep saying, I am afraid I am going to fall and break my hip.”
DeGregory tried Robbins’ predictive model and the test showed that she faces just a 0.5 percent chance of a fracture over five years. “I am so thankful,” she said. “I told my granddaughter, ‘I am ready to go.’”