Assessing fracture risk in patients with osteoporosis

In the past the management of osteoporosis centred on the use of diagnostic thresholds based on bone mineral density (BMD) measured at the spine or hip by dual x-ray absorptiometry (DXA). Previous guidance was based on an opportunistic case-finding strategy whereby the presence of clinical risk factors would prompt clinicians to measure BMD. Those patients with a BMD value that fell within the range of osteoporosis were considered for treatment. More recently it has been found that the presence of several of these risk factors is associated with a fracture risk greater than can be accounted for by BMD alone. Assessment of fracture risk therefore needs to take into account specific risk factors that contribute to fracture risk as well as BMD. NICE recommends that assessment of fracture risk should be considered in all women > or = 65 and all men > or = 75 years, and women < 65 and men <75 years if they have risk factors. When assessing an individual's risk of fracture, absolute risk should be estimated. Either FRAX (without a BMD value if a DXA scan has not been undertaken before) or QFracture should be used, within their allowed age ranges, to estimate 10-year predicted absolute fracture risk. BMD should not be routinely measured to assess fracture risk without prior assessment using FRAX (without a BMD value) or QFracture. FRAX and QFracture do not give the same estimates of absolute risk. The reasons lie in the different calibrations used. In the UK model of FRAX the risk algorithm is superimposed on, or calibrated to, the epidemiology of fracture (and mortality) incidence in the UK. The QFracture output reflects the incidence of fracture contained within the primary care database used to derive the tool.