Answer


To calculate the risk of a fracture compared to women of the same age, you must use the Z-score. The relative risk using lumbar spine measurements is 1.5 for each standard deviation, so she would be about 2.5 times the risk of a vertebral fracture. The relative risk at the hip is about 2.6 for each standard deviation. Thus, the estimated risk of hip fracture is only two-fold increased.

The absolute risk for a hip fracture in this case is less than one per 1000 women in the next year. The risk of ANY osteoporotic fracture is 5% over the next ten years. She does NOT have a seven-fold increased risk.

Also, a loss of 4% is not significant. The reproducibility of the machine is about 2%, and for an individual the loss must be greater than 6%.

Finally, it is not indicated to give alendronate to premenopausal women who are not taking prednisone and who do not have bone density in the osteoporosis range.

Updated 8/8/05