Appendix 1

World Health Organization definitions for osteopenia and osteoporosis5

World Health Organization Definitions of T Score
T Score: Most commonly, dual-energy X-ray absorptiometry (DXA) test results are compared to the ideal or peak bone mineral density (BMD) of a healthy 30-year-old adult, and are given as a T score. A score of 0 means the BMD is equal to the norm for a healthy young adult. Differences between the patient's BMD and that of the healthy young adult norm are measured in units measured as standard deviations (SDs). The more SDs below 0, indicated as negative numbers, the lower the BMD and the higher your risk of fracture.
Normal T score at or above −1.0
Osteopenia T score at or between −1.0 and −2.5
Osteoporosis T score at or less than −2.5