A tool developed by WHO to assess bone fracture risk underestimates the vulnerability in certain age groups and circumstances, according to a study published in The Journal of Clinical Endocrinology & Metabolism.
The Fracture Risk Assessment Tool (FRAX) — created to predict the likelihood that adults aged 40 to 90 years will break a bone in a fragility fracture (FF) and designed to help physicians identify osteoporosis cases not diagnosed through bone mineral density tests — fails to show risks in people younger than 65 years and those treated for a single broken bone, researchers in Canada found.
“Although FRAX is a helpful tool and provides important information, it should not be used as the unique and definitive gold standard for determining whether or not to treat a patient for osteoporosis or weakening bones,” Gilles Boire, MD, of the University of Sherbrooke in Quebec, Canada, said in a press release. “The test fails to identify some patients who would benefit from treatment to prevent future fractures.”
In a prospective cohort, Boire and colleagues gauged 10-year fracture risks among 1,399 patients identified as having a FF at older than 50 years. They used a Canadian form of the tool called BMI-FRAX, which incorporates national data on fracture rates, and scores were calculated before and after FF. Recurrent FF were recorded for 4 years.
Results showed high BMI-FRAX scores for 42.7% of patients before FF and 56.4% after FF. Most participants at low or moderate risk before their initial FF were men younger than 65 years or without previous FF. Follow-up showed recurrent FF in 108 patients. Sensitivity of post-FF FRAX to predict a recurrent incident was 71.3% and specifically lower in patients younger than 65 years (13%) and without previous FF (63%) at inclusion.
“The FRAX-BMI scores were below the Canadian threshold for treatment in more than half the patients at the time of a FF and in close to a third of patients with recurrent FF,” the researchers wrote. “FRAX-BMI severely underestimates the FF risk in patients under 65 years old, and after a single FF.”
Disclosure: Researchers received lecture fees or advisory board fees from Merck Canada, Procter&Gamble Canada, sanofi-aventis Canada, Amgen Canada, Novartis Canada Inc., Eli Lilly Canada and Servier Canada Inc. One researcher is an employee of Merck Canada. See study for full list of funding.