The Area Resources File (ARF) maintained by the Health Resources and Services Administration is a prominent source of information on the area in which each hospital is located. The ARF is a computerized health resources information system that contains more than 7,000 variables at the county level that could be aggregated to other geographic groupings such as MSAs/PMSAs. The ARF integrates data from a variety of sources, including the AHA, Bureau of Census, Interstudy, CMS and the VA. The variables include information on health care facilities and professions, population characteristics and economic data, and utilization. The 2000 release was available for our analyses, which draws most data elements from 1998.