Economics of immunization information systems in the United States: assessing costs and efficiency.

BACKGROUND: One of the United States' national health objectives for 2010 is that 95% of children aged te important progress- child participation in most IIS has increased slowly- in part due to limited economic knowledge about IIS operations. Should IIS need further improvement- characterizing costs and identifying factors that affect IIS efficiency become crucial. METHODS: Data were collected from a national sampling frame of the 56 states/cities that received federal immunization grants under U.S. Public Health Service Act 317b and completed the federal 1999 Immunization Registry Annual Report. The sampling frame was stratified by IIS functional status- children's enrollment in the IIS- and whether the IIS had been developed as an independent system or was integrated into a larger system. These sites self-reported IIS developmental and operational program costs for calendar years 1998-2002 using a standa