Prevention, Screening and Health Maintenance
Family Medicine Clerkship
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Upon completion of this unit, you will be familiar with:

What is osteoporosis?
What are the risk factors for osteoporosis?

Risk factors for osteoporosis include:

How do patients with osteoporosis present or when would you suspect osteoporosis?
What are the commonly used types of peripheral bone density measurements and how do they compare? Which is the gold standard?

Dual-energy X-ray Absorptiometry (DXA):

Quantitative CT (QCT):

What bone density measurement site correlates best with clinically important fractures?
Case 1

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.

Case 2:

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.

What is a T-score?

T-SCORE = the number of standard deviations the bone mineral density measurement is above or below the YOUNG-NORMAL MEAN bone mineral density.

What is a Z-score?

Z-SCORE = the number of standard deviations the measurement is above or below the AGE -MATCHED MEAN bone mineral density.

How do you use T and Z scores in clinical decision?

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:

What factors contribute to the estimate of the annual cost of screening all potential subjects in United States?

Cost of the program depends on:

How do you justify the cost of annual screening for osteoporosis?
Required Images: