PATTERNS OF FRACTURE AMONG THE UNITED-STATES ELDERLY - GEOGRAPHIC ANDFLUORIDE EFFECTS

The purpose of this study was to examine whether geographic area or wa ter fluoride were related to the occurrence of fractures among the eld erly in the United States. We used a 5% sample of the white U.S. Medic are population, aged 65 to 89 years during the period 1986-1990, to id entify fractures of the hip, proximal humerus, distal forearm, and ank le. The association of geographic region and fluoridation status with fracture rates was assessed using Poisson regression. We found that ra tes of hip fracture were generally lower in the northern regions of th e United States and higher in the southern regions. For fractures of t he distal forearm and proximal humerus, lower rates were found in the Western states, and higher rates in the East. No discernible geographi c pattern was found for ankle fractures. Adjustment for water fluorida tion did not influence these results. Independent of geographic effect s, men in fluoridated areas had modestly higher rates of fractures of the distal forearm and proximal humerus than did men in nonfluoridated areas; no such differences were observed among women, nor for fractur es of the hip or ankle among either men or women. In conclusion, our d ata suggest that fractures of the distal forearm and proximal humerus have etiologic determinants distinct from those of fractures of the hi p or ankle.