Supplemental calcium for the prevention of hip fracture: potential health-economic benefits.

We assessed the cost-effectiveness of daily calcium supplementation for the prevention of primary osteoporotic hip fractures. The assessment was based on our meta-analysis of the published relative-risk estimates from 3 double-masked, placebo-controlled, clinical trials and our analysis of raw data from the National Health and Nutrition Examination Survey 1988-1994 on the daily intake of calcium supplements by adults in the United States. These data were then used to estimate the preventable proportion of hip fractures. The 1995 National Hospital Discharge Survey database provided the number and demographic characteristics of patients discharged with a primary diagnosis of hip fracture, as well as their discharge destination. The 1990 itemized costs of hip fractures, as estimated by the US Congress Office of Technology Assessment, were inflated to 1995 dollars using the medical care component of the Consumer Price Index. Using these inflated itemized costs, we then estimated the weighted average expenditures, reflecting both the types of services associated with specific hospital-discharge destinations and the demographic characteristics of discharged patients. The cost of supplements containing 1200 mg/d of elemental calcium for the mean duration (34 months) of the 3 clinical trials was calculated on the basis of 1998 unit-price and market-share data for 6 representative products. For 1995, the data indicate that 290,327 patients aged > or =50 years were discharged from US hospitals with a primary diagnosis of hip fracture, at our estimated direct cost of $5.6 billion. Based on the risk reductions seen in the 3 trials, we estimated that 134,764 hip fractures and $2.6 billion in direct medical costs could have been avoided if individuals aged > or =50 years consumed approximately 1200 mg/d of supplemental calcium. Additional savings could be expected, because this intervention is also associated with significant reductions in the risk for all nonvertebral fractures. Comparing the cost of calcium with the expected medical savings from hip fractures avoided, it is cost-effective to give 34 months of calcium supplementation to women aged > or =75 years in the United States. If, as the published studies suggest, shorter periods of supplementation result in an equivalent reduction in the risk of hip fractures, calcium supplementation becomes cost-effective for all adults aged > or =65 years in the United States. The data support encouraging older adults to increase their intake of dietary calcium and to consider taking a daily calcium supplement. Even small increases in the usage rate of supplementation are predicted to yield significant savings and to reduce the morbidity and mortality associated with hip fracture at an advanced age.