For years, the way providers have assessed the risk of fracture in aging patients is by looking at bone mineral density (BMD), as measured by bone densitometry. But consensus is emerging that a much better way to assess fracture risk is by taking into account BMD measures or T-scores in combination with other key risk factors, especially age and previous fractures. In fact, investigators report that at least some clinical guidelines will soon recommend that clinicians adopt a new approach toward assessing risk that uses a formula that considers several different weighted risk factors to estimate what they are calling absolute fracture risk.
The new approach will first be outlined by the World Health Organization (WHO) in a technical document that the organization is expected to publish by the end of this year. But experts tell DMA that prominent U.S.-based organizations such as the National Osteoporosis Foundation (NOF) will quickly follow WHO’s lead in publishing guidelines of their own that are reflective of WHO’s work.
The move in this direction is based on years of extensive research into the various factors that contribute to the risk of fracture, and it is expected to trigger a significant change in the way providers determine when and whether to prescribe treatment for patients who exhibit signs of bone-thinning disease. Although providers will still have to rely on their clinical skills to make individualized treatment decisions, experts familiar with the new approach tell DMA that it will offer improved guidance about how to proceed.
New approach is an improvement
Currently, providers generally use T-scores to determine whether to prescribe treatment that can enhance bone preservation. This is based on cut-points that WHO established in 1994 in order to have operational definitions for osteoporosis, low BMD or osteopoenia, and normal BMD. The problem with these definitions, however, is that they don’t tell the whole story, according to Ethel Siris, MD, director of the Toni Stabile Osteoporosis Center at Columbia University Medical Center in New York City and president of NOF.
“While it is true that whether a person is 50, 70, or 90 years of age, if [he or she has] a T-score of -2.5 or -3, [his or her] risk of fracture is much higher than if [his or her] T-score is -2 or -1.7 . . . It is also true that if you have a 50-year-old with a T-score of -2.5 at the spine, which would be called osteoporosis, [his or] her 10-year risk of fracture turns out to be lower than that of a 70-year-old who has a T-score of -2, which would be called osteopoenia,” explains Siris.
Studies show that older age significantly enhances the risk of fracture in both women and men, and there are other factors that enhance risk as well, but these factors are not reflected in T-scores. Consequently, what the concept of absolute fracture risk does is take into account these other risk factors so that the provider can make better treatment decisions, says Siris. “Now that we have a lot of good treatments, we really need to do a better job of assessing the true risk in order to assure that those at highest risk get treated,” she says, adding that the new approach also enables healthcare organizations do a better job of allocating their resources.
Clinical skills still required
To determine a patient’s absolute fracture risk, a weighted algorithm will be used to arrive at a person’s 10-year risk of fracture. To simplify this process for providers, Siris anticipates that software will be made available that can be loaded directly onto bone densitometry machines so that the appropriate calculations can be made while the patient is undergoing a bone density scan. The process will require the technologist to ask the patient a few questions so that other key risks will be factored into the equation along with the patient’s BMD measurement.
In addition to the BMD measurement, the two most important factors are whether a patient has suffered a previous fracture and older age. Other factors that heighten fracture risk include tobacco use, family history of hip fracture, rheumatoid arthritis, and excessive use of alcohol.
Although the specifics of the new algorithm have not yet been published, Siris says that the approach will make it much harder for a provider to fail to treat a person who has recently broken a hip. “The hip fracture will be weighted so heavily that the person could wind up, correctly, with maybe a 25% or 30% 10-year risk of another fracture,” says Siris, adding that today, providers may neglect to treat such a patient if he or she has a T-score that does not meet the current definition of osteoporosis. “The very highest-risk patients—those who have had a fragility fracture—would score very high on [the algorithm] so that it would be almost malpractice not to treat them.”
In addition to making it much more likely that the people at highest risk receive treatment, Siris expects that the new approach will also eliminate at least some of the confusion among providers concerning what to do about osteopoenia, which signifies a BMD level that is below normal but not to the level of osteoporosis. “If you have a 50-year-old patient who has a T-score of 1.9 at the hip and no other fractures, the patient’s 10-year fracture risk may be relatively low,” notes Siris. On the other hand, she notes that a 73-year-old patient with the same T-score is likely to have a fracture probability that puts him or her above the treatment threshold because of his or her age and osteopoenia.
Siris emphasizes that although the algorithm to determine absolute fracture risk will provide guidance to physicians, it will not tell them how to treat or what, if any, agent to use. In addition, she stresses that it does not take every possible circumstance into account. “What do you do if you have a 70-year-old patient who has a -pretty decent T-score, but [he or] she falls down a lot?” says Siris, noting that falls and many other issues are not part of the algorithm. “The doctor is still going to have to use judgment, but for a great many providers, the algorithm will be very helpful as a broad approach.”
Provider education is critical
Of course, the algorithm can only apply to patients who undergo bone densitometry. Medicare covers the procedure for all women 65 or older. But according to CMS, in 2005 only about 20% of patients who were eligible for bone densitometry actually received it, says Meryl LeBoff, MD, director of the Skeletal Health and Osteoporosis Center at Brigham and Women’s Hospital in Boston. In addition, LeBoff explains that many younger women with various risk factors—such as a history of anorexia, athletic amenorrhea, or use of certain drugs such as glucocorticoids—should undergo BMD testing as well, but the number of referrals for such tests is nowhere near where it should be.
“Bone density exams are widely available in major academic medical centers, cities, and outpatient settings, so I don’t know why doctors are not ordering these tests,” says LeBoff, adding that 40% of women over the age of 50 will sustain an osteoporotic fracture. “Physicians do far better with a patient who comes in with cardiac symptoms, so it is a matter of increasing awareness and education about the importance of bone health and the health consequences of osteoporotic fracture.”
LeBoff is hopeful that the new approach toward assessing absolute fracture risk will offer the added benefit of enhancing the visibility of bone health in women as well as in men, although bone loss tends to develop at a later age in men. “[Men] are [also] at risk of a fracture,” she says, noting that 29% of hip fractures occur in men.