Tara Haelle
January 06, 2016
Two thirds of women receiving medication for osteoporosis potentially did not need treatment, according to a retrospective cohort study published online January 4 in JAMA Internal Medicine. In fact, half of these women with possibly inappropriate prescriptions were younger and without risk factors that would have indicated screening, found Joshua J. Fenton, MD, MPH, from the University of California Davis Medical Center in Sacramento, and colleagues.
“In our population, nearly one-third of the women had non-main-site osteoporosis, which was disproportionately attributable to lateral lumbar spine osteoporosis,” the authors write. “These results suggest that either physicians are unaware of International Society for Clinical Densitometry guidelines that lateral lumbar spine bone mineral density should not be used for osteoporosis diagnosis or they assume that osteoporosis observed at any site warrants treatment.”
The researchers analyzed electronic health records and radiology records of 6150 women, aged 40 to 85 years, who underwent dual-energy X-ray absorptiometry (DXA) screening for osteoporosis in the University of California Davis health system between January 2006 and December 2011. None of the women had received treatment before their DXA screening as far back as 2002, but 31.1% of them received new osteoporosis drug treatment during the study window. About one in five women (20.4%) had at least one osteoporosis risk factor: body mass index of 20 kg/m2or greater, glucocorticoid use, possible secondary osteoporosis, previous high-risk fracture, rheumatoid arthritis, or alcohol abuse. However, 60.1% of the women who underwent DXA screening were between ages 40 and 64 years and lacked any osteoporosis risk factors.
The authors defined normal T scores as greater than −1.0, whereas those greater than −2.5 through −1.0 were considered osteopenia, and those less than −2.5 were considered osteoporosis. Main sites for osteoporosis diagnosis included anterior-posterior spine and femoral neck, based on International Society for Clinical Densitometry recommendations. Non-main sites included lateral lumbar, Ward triangle, forearm, and radius sites.
Of all the women, 14.2% had osteoporosis at a main site, and 73.5% of them received new drug therapy. Just under a third (32.8%) of the women had osteoporosis at a non-main site, and nearly half of them (47.7%) received medication. The remaining 53.1% of women had normal T scores or isolated osteopenia at a main or non-main site.
“Because non-main-site osteoporosis or isolated osteopenia occurred commonly, women with non-main-site osteoporosis accounted for 50.3% of new drug prescriptions (95% CI, 48.0%-52.5%), and those with osteopenia accounted for 15.8% (95% CI, 14.2%-17.5%),” the authors report. Of all the women receiving medication, 66.4% had no osteoporosis or only had non-main-site osteoporosis, and half of these women (50.9%) were between ages 40 and 64 with no risk factors.
“To avert osteoporosis overtreatment, health care systems should either ensure that radiologists report T scores only for sites consistent with International Society for Clinical Densitometry diagnostic guidelines or provide high-quality decision support so that physicians do not make osteoporosis diagnoses based on nondiagnostic sites,” the authors write.
Even if some of the women assessed in the study had a different risk factor than those considered, such as smoking or parental hip fracture, many women with no risk factors were overtreated, write Tiffany Y. Kim, MD, and Anne L. Schafer, MD, both from the San Francisco Veterans Affairs Medical Center and the University of California San Francisco, in an invited commentary.
“Although the fracture reduction benefit of bisphosphonates in osteoporosis is greater than the risk of adverse events, such as osteonecrosis of the jaw or atypical femoral fracture, these rare complications as well as cost considerations oblige us to avoid treatment in those less likely to benefit,” they write. They do note that some of the prescriptions may have represented appropriate treatment based on their provider’s assessment that they were at a high risk for fracture. “For women without main-site osteoporosis who were older or had multiple risk factors, it is unclear whether treatment was inappropriate,” they write.
They acknowledge both the importance of bone mineral density for osteoporosis assessment as well as diagnostic evaluation based on “a more comprehensive assessment of skeletal fragility,” leaving the challenge of “identifying individuals with osteopenia who have a fracture risk high enough to warrant pharmacotherapy.”
Therefore, they write, “the National Osteoporosis Foundation recommends pharmacotherapy for postmenopausal women and men 50 years or older with osteoporosis-range [bone mineral density (BMD)] as per [International Society for Clinical Densitometry] criteria; a history of hip or spine fracture (and thus demonstrated skeletal fragility); or lowest T score of −1.0 or less but higher than −2.5 plus a 10-year probability of hip fracture of 3% or more or major osteoporotic fracture of 20% or more based on the World Health Organization’s Fracture Risk Assessment tool (https://www.shef.ac.uk/FRAX). This tool incorporates femoral neck BMD and several clinical risk factors to estimate absolute fracture risk, although it can also be used without BMD data.”
Meanwhile, many high-risk patients continue to be missed in terms of screening and treatment, they note: Only a quarter of women with a fragility fracture undergo DXA or receive osteoporosis medication within the next 6 months, they write. They recommend a fracture liaison service or vertebral fracture assessment to identify more of these women.
The research was funded by the National Institutes of Health and the Agency for Healthcare Research and Quality. The authors have disclosed no relevant financial relationships. Dr Schafer receives support from the Department of Veterans Affairs, Veterans Health Administration, Clinical Science Research and Development Service, Career Development Award. Dr Kim has disclosed no relevant financial relationships.
JAMA Intern Med. Research letter extract, Commentary extract