Report1994
Assessment of Fracture Risk and its Application to Screening for Postmenopausal Osteoporosis: Report of a WHO Study Group
World Health Organization
Defines osteoporosis operationally as bone mineral density 2.5 standard deviations or more below the young adult mean, arguing that a single quantitative threshold measured by densitometry is necessary before fracture risk can be screened for and treated systematically.
link checked 17 Sept 2026