Osteoporosis is a bone disease that develops because of bone loss. The result is weak and brittle bones that are prone to fractures even from low-impact movements. To find out if you have or are at risk for osteoporosis, you will need a bone density test. A bone density scan produces a number called a T-score.
T-scores are used to determine primary osteoporosis, which exists on its own without any other cause. The test is used most often for people over the age of 50 who experience accelerated bone loss and for people who have already had a fracture caused by osteoporosis.
The test is used most often for people over the age of 50 who experience accelerated bone loss and for people who have already had a fracture caused by osteoporosis. Z-scores are designed to identify if there is a secondary cause of bone loss. They are often used for younger adults, children, or premenopausal women. 4
This score is considered low bone density. People in this range are at medium risk for fracture or osteoporosis. Anything below -2.5 indicates osteoporosis and a high risk for fractures. People with these scores have osteoporosis that ranges in severity.
The “T” in T-score represents the number of standard deviations, or units of measurement, your score is above or below the average bone density for a young, healthy adult of your same sex. Lower T-scores mean you could be at risk for developing osteoporosis or that you might already have the condition.
Osteoporosis is a disease that causes bones to become thin and weak, increasing your risk for fractures (broken bones). A bone density test can diagnose osteoporosis when your T-score is -2.5 or below. The lower your bone mass measurement, the greater your risk for fracture.
T-scoreT-scoreWhat your score means-1 and aboveYour bone density is considered normal.Between -1 and -2.5Your score is a sign of osteopenia, a condition in which bone density is below normal and may lead to osteoporosis.-2.5 and belowYour bone density indicates you likely have osteoporosis.Sep 25, 2021
A T-score within 1 SD (+1 or -1) of the young adult mean indicates normal bone density. A T-score of 1 to 2.5 SD below the young adult mean (-1 to -2.5 SD) indicates low bone mass. A T-score of 2.5 SD or more below the young adult mean (more than -2.5 SD) indicates the presence of osteoporosis.
Z-Test or T-test, what test should I use? When you know the population standard deviation you should use the Z-test, when you estimate the sample standard deviation you should use the T-test. Usually, we don't have the population standard deviation, so we use the T-test.
A T-score between −1 and −2.5 indicates that you have low bone mass, although not low enough to be diagnosed with osteoporosis. A T-score of −2.5 or lower indicates that you have osteoporosis. The greater the negative number, the more severe the osteoporosis.
DEXA scores are reported as "T-scores" and "Z-scores." The T-score is a comparison of a person's bone density with that of a healthy 30-year-old of the same sex. The Z-score is a comparison of a person's bone density with that of an average person of the same age and sex.
T scores in psychometric testing are always positive, with a mean of 50. A difference of 10 (positive or negative) from the mean is a difference of one standard deviation. For example, a score of 70 is two standard deviations above the mean, while a score of 0 is one standard deviations below the mean.