Osteoporosis risk tools perform well in men aged over 50 years
MedWire News: Osteoporosis risk assessment tools appear to perform well in men aged 50 years or more, but the best cut-off values for bone mineral density (BMD) values differ from those recommended for postmenopausal women, conclude Portuguese investigators.
Generalized screening is not cost-effective for the detection of osteoporosis in men, of whom one in five aged over 50 years will experience an osteoporosis-related fracture. Consequently, tools are required to identify patients who are most likely to benefit from BMD testing.
To examine the utility of three osteoporosis risk assessment tools, Pedro Machado and colleagues from Coimbra University Hospital applied the body weight criterion (BWC), the osteoporosis self-assessment tool for Asians (OSTA), and a modified version of the OSTA equation (OST) to 250 randomly selected men aged 50 years or above.
The team used cut-off values that had previously been validated in postmenopausal women, plus three additional cut-off values. BMD values as assessed by dual-energy X-ray absorptiometry (DXA) were used as the gold standard for diagnosing osteoporosis, and the World Health Organization (WHO) thresholds were used to classify patients as normal, osteopenic, and osteoporotic.
As reported in the journal Osteoporosis International , 32.2% of men were classified as normal, 51.0% as osteopenic, and 16.8% as ostoeporotic. The percentage of men with osteoporosis increased with age, from 14.4% among men aged between50 and 70 years to 24.5% among men aged above70 years.
Age was significantly correlated with femoral neck and total hip T-scores, but not with lumbar spine T-scores.
Maximum sensitivity was achieved with the highest cut-offs for OST (<4), OSTA (<4), and BWC (<80 kg), at 85.3%, 76.5%, and 82.4%, respectively. However, these cut-offs were associated with very low specificities, at 32.7%, 42.9%, and 35.7%, respectively.
The greatest areas under the receiver operating characteristics curves were for cut-offs on the OST, OSTA, and BWC of <3, <3, and 75 kg, respectively, at 0.632, 0.659, and 0.674, respectively. The sensitivities for the cut-offs were a respective 76.5%, 73.5%, and 73.5%, while the negative predictive values were 91.3%, 91.6%, and 92.0%.
The team says: “Our results confirm the validity of the OST, OSTA, and BWC to support physicians and public health authorities to focus DXA testing on individuals at increased risk of osteoporosis, thus increasing its cost-effectiveness.
“With BWC being the simplest one and having a statistical performance that is similar to the others, our data strongly support the use of body weight as the preferred method to select men for DXA scanning.”
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By Liam Davenport