Clinical epidemiology and osteoporosis. Measures and their interpretation.

Identifying patients with a high risk of fracture and monitoring a patient's therapeutic response are important. Current methods to evaluate the risk of fracture include the measurement of bone mineral density as well as other risk factors, including those associated with the risk of falling. Several considerations are important in defining the risk for fracture. There is currently no level of bone mineral density at which the risk of fracture is zero, that is, some high-risk women will not have a fracture and some low-risk women will. The monitoring of high-risk individuals for subtle changes in their bone status is not economically feasible at this time. Given the precision of current measurement technology, it is more reasonable to expect to monitor individuals on a 3- to 5-year basis rather than every 6 months to 1 year. There is no single optimal site at which measurement is highly precise and predictive of bone mineral density measurement at other skeletal locations. Currently, measurement of the femoral neck seems to have the most universal applicability. Measurement of bone turnover markers remains more effective as a research tool and is less effective as a method to diagnose or monitor the bone status of individual patients.