METAANALYSIS OF HOW WELL MEASURES OF BONE-MINERAL DENSITY PREDICT OCCURRENCE OF OSTEOPOROTIC FRACTURES

Objective-To determine the ability of measurements of bone density in women to predict later fractures. Design-Meta-analysis of prospective cohort studies published between 1985 and end of 1994 with a baseline measurement of bone density in women and subsequent follow up for frac tures. For comparative purposes, we also reviewed case control studies of hip fractures published between 1990 and 1994. Subjects-Eleven sep arate study populations with about 90 000 person years of observation time and over 2000 fractures. Main outcome measures-Relative risk of f racture for a decrease in bone mineral density of one standard deviati on below age adjusted mean. Results-All measuring sites had similar pr edictive abilities (relative risk 1.5 (95% confidence interval 1.4 to 1.6)) for decrease in bone mineral density except for measurement at s pine for predicting vertebral fractures (relative risk 2.3 (1.9 to 2.8 )) and measurement at hip for hip fractures (2.6 (2.0 to 3.5)). These results are in accordance with results of case-control studies. Predic tive ability of decrease in bone mass was roughly similar to (or, for hip or spine measurements, better than) that of a 1 SD increase in blo od pressure for stroke and better than a 1 SD increase in serum choles terol concentration for cardiovascular disease. Conclusions-Measuremen ts of bone mineral density can predict fracture risk but cannot identi fy individuals who will have a fracture. We do not recommend a program me of screening menopausal women for osteoporosis by measuring bone de nsity.