Urbanization

In Health, United States, death rates are presented according to the urbanization level of the decedent's county of residence. Counties and county equivalents were assigned to one of five urbanization levels based on their classification in the Urban Influence code system (December 1996 Revision) developed by the Economic Research Service, U.S. Department of Agriculture. There are three levels for metropolitan counties and two levels for nonmetropolitan counties. The categorization of counties as metropolitan or nonmetropolitan in the Urban Influence code system is based on the June 1993 OMB definition of metropolitan areas (the application of the 1990 metropolitan area standards to the 1990 decennial census data). Metropolitan areas include metropolitan statistical areas (MSAs), consolidated metropolitan statistical areas (CMSAs), and primary metropolitan statistical areas (PMSAs).

The Urban Influence code system classifies metropolitan counties as either large metro (counties in MSA/PMSAs of 1 million or more population) or small metro (counties in MSA/PMSAs of less than 1 million population). For Health, United States, the large metro category of the Urban Influence code system was divided into two urbanization levels: large central metro and large fringe metro. Thus, metropolitan counties were assigned to one of three metropolitan urbanization levels: (a) large central--counties in large (1 million or more population) MSA/PMSAs that contain all or part of the largest central city of the MSA/PMSA; (b) large fringe--counties in large (1 million or more population) MSA/PMSAs that do not contain any part of the largest central city of the MSA/PMSA (counties in a few PMSAs with less than 1 million population were assigned to the large fringe urbanization level because the PMSA in which they are located is adjacent to a large central county of the CMSA); and (c) small--counties in small (less than 1 million population) MSA/PMSAs.

The Urban Influence code system divides nonmetropolitan counties into seven categories based on adjacency to a metropolitan area and size of the largest city. A county is considered to have a city with a specified size if it includes all or part of the city. The seven categories were collapsed into two categories: (d) nonmetro counties with a city of 10,000 or more population and (e) nonmetro counties without a city of 10,000 or more population.

SOURCE: Health, United States

Related Links
Economic Research Service's Measuring Rurality: Rural-Urban Commuting Area Codes
Economic Research Service's Map of Counties by Urban Influence, 1990

This page last reviewed June 17, 2004