The strategy differs from NOGG in that FRAX is always used with BMD. Indeed, a BMD test is a prerequisite. Additionally, a fixed intervention threshold is used at all ages, whereas the NOGG strategy uses an age-dependent threshold. The rationale for a fixed threshold is based on the fracture probability at which intervention becomes cost-effective in the USA and the 20% threshold is, therefore, not relevant for any other country. Other assessment models As well as the FRAX tool, other fracture risk calculators are available online which include the Garvan fracture GW3965 clinical trial risk calculator and QFracture™ [69, 70]. Their comparative features are summarised in Table 9. The QFracture™ tool is based on
a UK prospective open cohort
study of routinely collected data from 357 general practices on over 2 million men and women aged 30–85 years (www.qfracture.org). Like the FRAX tool, it takes into account history of smoking, alcohol, corticosteroid use, parental history (of hip fracture or osteoporosis) and several secondary causes of osteoporosis. Unlike FRAX, it also includes a history of falls (yes/no only over an unspecified time frame) and excludes previous fracture history and BMD. It has been selleck chemicals llc internally validated (i.e. from a stratum of the same population) and also externally validated in the UK [126]. Table 9 Comparative features of three fracture risk assessment algorithms Dubbo/Garvan Neuronal Signaling inhibitor Qfracture FRAX Externally validated Yes (a few countries) Yes (UK only) Yes Calibrated No Yes (UK only) Yes Applicability Unknown UK 45 countries Falls as an input variable Yesa Yes No BMD as an input variable Yes No Yes Prior fracture as an input variable Yesa No Yes Family history as an input variable No Yes Yes Output Incidence Incidence Probability Treatment responses assessed No No Yes aAnd number of falls/prior fractures The Garvan tool (www.garvan.org.au) is based on data from participants enrolled in the Australian Dubbo Osteoporosis epidemiology study of approximately
2,500 men and Inositol monophosphatase 1 women age 60 years or more. It differs from FRAX by including a history of falls (categorised as 0, 1, 2 and >2 in the previous year) and the number of previous fragility fractures (categorised as 0, 1, 2 and >2), but does not include other FRAX variables. The output of the tool differs from FRAX in that it reports the risk of a larger number of fracture sites (additionally includes fractures of the distal femur, proximal tibia/fibula, distal tibia/fibula, patella, pelvis, ribs sternum, hands and feet excluding digits). As in the case of the QFracture, the Garvan tool captures fall risk. A fundamental difference between these risk models and FRAX is that the parameters of risk differ (incidence vs. probabilities) so that comparative data are not readily interpreted [127] (Fig. 10).