Better Osteo Screening Suggested
Canadian study finds two ways more effective than current 'gold standard' in U.S.
TUESDAY, July 3 (HealthDayNews) - There are better and simpler options than a national foundation's guidelines to help determine which women need osteoporosis screening, a Canadian study says.
Two options, both clinical practice guidelines, catch more women who are at risk for the bone disease and they also ferret out those who don't really need testing, researchers say.
Considered the "gold standard" in the United States, the complex guidelines established by the National Osteoporosis Foundation (NFO) take into account 30 risk factors for doctors to assess in determining which women need the low bone mineral density (BMD) test.
The clinical practice guidelines the study endorses are much simpler. One looks at age, weight, estrogen use, previous fractures, rheumatoid arthritis and race. The other says that women over 65 years old who weigh less than 132 pounds and have had estrogen therapy need to be tested.
But the chairman of the NOF's scientific advisory committee says the findings may have no practical application in the United States. The Canadian population is less diverse -- 97 percent of the women in the study were white -- and additional studies targeted at different populations are needed to figure out which rule will work best in this country, Dr. Lawrence Raisz says.
Figuring out which women should be tested for BMD is an important strategy in preventing osteoporosis, says lead study author Suzanne Cadarette, a research associate at the Women's College Ambulatory Care Center in Toronto.
Her study compared the NOF guidelines with four clinical-decision rules. The simplest of the four says that a woman weighing more than 154 pounds doesn't need a bone density test. Two others are based on age, weight and estrogen use. "And the fourth [and most complex] is based on age, weight, estrogen use, history of minimal trauma fracture after 45 years of age, rheumatoid arthritis, and race," Cadarette says.
The team studied 2,365 postmenopausal women 45 and older who had no bone disease but whose bone mineral density was known. Each of the four rules was applied to the women, along with only five of the NOF guideline's 30 risk factors.
"We found that two of the decision rules - the most complex and the decision rule that uses age 65 or older, weigh less than 132 pounds and estrogen use were the best rules in predicting who needed a bone density test," Cadarette says. "And those two were better than the NOF guidelines because they selected less of the women who had normal bone density."
The findings appear in the July 3rd issue of the Journal of the American Medical Association.
Osteoporosis affects an estimated 10 million Americans, mostly postmenopausal women whose bones are weakened by a lack of the hormone estrogen, which is chiefly produced by the ovaries. The disease makes people vulnerable to crippling, even life-threatening fractures. According to the National Osteoporosis Foundation, 18 million more have low bone mass, placing them at increased risk for osteoporosis.
The study may be good for Canadians, but whether the findings will hold true in the United States is still up in the air, says the National Osteoporosis Foundation.
"I think this is a very good study for validation of decision-making procedures in Canada," adds Raisz, who chairs the NOF's scientific advisory board and is program director of the University of Connecticut's Lowell P. Weicker, Jr. General Clinical Research Center. "But we don't know yet if the same would hold true for the American population. We are probably going to need new studies targeted at different populations to understand what rule would be most efficacious."
Raisz says the NOF guidelines are designed "to miss as few osteoporosis patients as possible and they are simple. Ultimately, what we are going to need are good studies of bone mineral density in both the spine and the hip in broad populations, in order to figure out what is the optimum way to select for bone mineral density."
Whatever the rule, doctors need to send more patients for the osteoporosis test, Raisz adds.
"It's consumer-driven right now," he says. "Our contention is that a lot more doctors should be using this test. Right now the patients say, 'I want a bone density test,' and they get one. The problem is that as few as 20 percent of people with fragility fractures are getting diagnosed and treated for osteoporosis."
What To Do
The National Osteoporosis Foundation currently recommends a bone density test for all women 65 and over and all postmenopausal women who have had a fracture. The foundation also recommends you get tested if you're postmenopausal and have the following risk factors: a personal history of fracture as an adult; a history of fracture in a first-degree relative; Caucasian race; dementia; frail health; cigarette smoking; low body weight; estrogen deficiency; lifelong low calcium intake; alcoholism; impaired eyesight despite adequate correction; recurrent falls; and inadequate physical activity.