A DXA scan measures bone density through a T-score and, together with the FRAX calculation tool, provides an estimate of fracture risk over ten years. In postmenopausal women from around age 65, screening with these methods has been shown to actually result in fewer bone fractures. In men, the evidence is considerably thinner and the clinical added value is less certain.
A DXA scan measures how strong your bones are, expressed as a so-called T-score. That score compares your bone density with that of young adults: a score down to roughly minus 1.0 is considered normal, between minus 1.0 and minus 2.5 is described as reduced bone density, and below minus 2.5 as osteoporosis. If you combine that result with the FRAX calculation tool, which also takes into account factors such as age, weight and any previous fractures, you get an estimate of the likelihood of a bone fracture in the next ten years.
That number is not a personal prediction but a probability estimate, comparable to how a weather forecast works. Where it becomes truly useful: in postmenopausal women, certainly from around age 65, it has been shown that screening with DXA and FRAX actually leads to fewer fractures, because timely treatment works. In men the evidence is considerably thinner, so the clinical value there is less certain.
A DXA scan places very little burden on the patient: the radiation dose is lower than that of a standard chest X-ray. You can request one through your general practitioner or specialist; it is reimbursed when there is a clear reason, such as postmenopausal status with risk factors, a previous fracture from a minor fall, or the use of certain medications that weaken bones. What you do with the result, that is, whether and how to treat, is always a conversation with your doctor, because the T-score and FRAX do not constitute a diagnosis on their own.
Strong evidence, based on 2 source(s), including controlled or causal research.