I. Bone density testing is indicated for: 1. Women aged ≥65 years or men aged ≥70 years (timing of periodic examinations is determined by initial results); 2. Postmenopausal women or men aged between 50 and 69 years with concomitant risk factors for osteoporosis (e.g., endocrine disorders, malabsorption) or based on the fracture risk calculation model (FRAX); 3. Women aged ≥50 years with more than 1 previous history of fracture. Vertebral imaging is indicated for: 1. women ≥ 70 years of age or men ≥ 80 years of age with a BMDT value ≤ -1.0 for the spine, hip, or femoral neck; 2. women between 65-69 years of age or men between 70-79 years of age with a BMDT value ≤ -1.5 for the spine, hip, or femoral neck; 3. postmenopausal women ≥ 50 years of age with the following risk factors: low-trauma fracture during adulthood traumatic fracture during adulthood; more than 3.8 cm reduction in height from normal during adolescence or more than 2.0 cm reduction in expected height from normal as assessed medically; and previous or ongoing long-term treatment with glucocorticoids. Epidemiology of osteoporosis Among Americans aged ≥50 years, the risk of osteoporosis is 16% for women and 4% for men; and there are at least 15 million fractures associated with osteoporosis each year, including 300,000 hip fractures and 700,000 vertebral fractures. Patients with fractures have reduced bone function, with approximately 1/3 of hip fracture patients admitted to hospital within 1 year, and a mortality rate associated with hip fractures of more than 20% within 1 year. And low BMD is one of the main risk factors for osteoporotic fractures, so its active treatment can effectively prevent fractures. Evidence-based medicine for osteoporosis There is no evidence that the diagnosis of osteoporosis reduces the risk of fracture or fracture-related mortality. Therefore, this recommendation is based on several studies concluding that treatment with bisphosphonates in female patients with osteoporosis reduces vertebral fractures. However, a pooled analysis of nine studies showed that this conclusion was not statistically significant. Numerous studies have shown that vertebral fractures can significantly increase the risk of developing secondary fractures. One study found that patients with a single vertebral fracture had a fourfold increased risk of secondary fracture. Another study found that the risk of two vertebral fractures could increase up to 12-fold. Other studies have shown that only 1/3 of vertebral fractures can be detected clinically and cannot be detected by testing BMD alone. In addition, patient height loss of more than 4 cm correlates with a 4-fold increase in vertebral fracture risk, and screening with vertebral body imaging is cost-effective. V. Clinical Implications In conclusion, several studies have shown that timely diagnosis and treatment of patients with osteoporosis can all significantly reduce the risk of fracture. After cost-benefit analysis, NOF recommends that patients with ≥3% risk of hip fracture within 10 years need to receive formal treatment.