Operationalizing Treat-to-Target for Osteoporosis

Treat-to-target (TTT) for osteoporosis is a concept for individualizing patient treatment decisions that focuses on achieving an acceptable level of fracture risk rather than response to treatment alone. While a response to treatment is essential in order to achieve an acceptable level of risk, it is not necessarily sufficient. Some patients have a good response to treatment yet remain at high level of fracture risk. Since there is no way to directly measure bone strength in patients treated for osteoporosis, a surrogate measurement must be used. Bone mineral density (BMD) is commonly used to select patients for treatment and has emerged as the most useful surrogate for assessing reduction of fracture risk after treatment is started. Recent large meta-regression studies have shown a robust correlation between larger increases in BMD with treatment and greater reductions in fracture risk. Application of TTT for osteoporosis involves assessing fracture risk before starting treatment and initiating treatment with an agent that is most likely to reduce fracture risk to an acceptable level, represented by a target BMD T-score, over a reasonable period of time. This review offers suggestions for implementing TTT for osteoporosis in clinical practice and managing patients who fail or succeed in reaching the target. More study is needed to fully validate the use of TTT for osteoporosis for initiating and modifying treatments to reduce fracture risk.