Prevention, Screening and Health Maintenance
Family Medicine Clerkship
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Osteoporosis
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Osteoporosis
Upon completion of this unit, you will be familiar with:
Risk factors for osteoporosis include:
Dual-energy X-ray Absorptiometry (DXA):
Quantitative CT (QCT):
A postmenopausal 53-year-old white woman comes to clinic for an annual physical. Her exam is normal. She has come across many advertisements regarding osteoporosis screening. What would you recommend?
A: Order bone mineral density scan
B: Empiric preventive treatment for osteoporosis
C: Need more clinical information prior to giving recommendations
Answer: C
For women over the age of 50 and under 65, you need at least one risk factor to recommend bone mineral density scan.
A 66 y/o white female comes to the clinic for routine follow up. She is concerned about osteoporosis and being that she is over 65, she qualifies for a bone mineral density scan. A DXA shows total hip bone mineral density 0.93 SD above the 66-year-old mean and 0.36 SD below the 25-year-old mean. T score is reported as -036 and her Z score is 0.93.
T-SCORE = the number of standard deviations the bone mineral density measurement is above or below the YOUNG-NORMAL MEAN bone mineral density.
Z-SCORE = the number of standard deviations the measurement is above or below the AGE -MATCHED MEAN bone mineral density.
A bone mineral density more than 2.5 standard deviations below the mean for a young healthy adult white woman identifies 30 percent of all postmenopausal women as having osteoporosis; half of these women will already have had a fracture.
The hip T-score is the site used in clinical decisions.
Z-score is less commonly used but may be helpful in identifying persons who should undergo a work-up for secondary causes of osteoporosis.
A Z-score changes over time in relation to the T-score.
Converting T-score to Z-score at the hip:
Cost of the program depends on: