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 doubl e-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 d ata were then used to estimate the preventable proportion of hip fractures. The 1995 National Hospital Discharge Survey database provided the number a nd demographic characteristics of patients discharged with a primary diagno sis of hip fracture, as well as their discharge destination. The 1990 itemi zed costs of hip fractures, as estimated by the US Congress Office of Techn ology Assessment, were inflated to 1995 dollars using the medical care comp onent 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 t he demographic characteristics of discharged patients. The cost of suppleme nts containing 1200 mg/d of elemental calcium for the mean duration (34 mon ths) of the 3 clinical trials was calculated on the basis of 1998 unit-pric e and market-share data for 6 representative products. For 1995, the data i ndicate that 290,327 patients aged greater than or equal to 50 years were d ischarged from US hospitals with a primary diagnosis of hip fracture, at ou r 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 i n direct medical costs could have been avoided if individuals aged greater than or equal to 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 nonvertebr al fractures. Comparing the cost of calcium with the expected medical savin gs from hip fractures avoided, it is cost-effective to give 34 months of ca lcium supplementation to women aged greater than or equal to 75 years in th e United States. If, as the published studies suggest, shorter periods of s upplementation result in an equivalent reduction in the risk of hip fractur es, calcium supplementation becomes cost-effective for all adults aged grea ter than or equal to 65 years in the United States. The data support encour aging older adults to increase their intake of dietary calcium and to consi der taking a daily calcium supplement. Even small increases in the usage ra te of supplementation are predicted to yield significant savings and to red uce the morbidity and mortality associated with hip fracture at an advanced age.