This item was estimated by matching the state and county FIPS code of the patient recorded at the time of diagnosis against 2003 files published by the United States Department of Agriculture Economic Research Service (http://www.ers.usda.gov/data-products/rural-urban-continuum-codes).
Rural-Urban continuum codes form a classification scheme that distinguishes metropolitan (metro) counties by the population size of their metro area, and nonmetropolitan (nonmetro) counties by degree of urbanization and adjacency to a metro area or areas. The metro and nonmetro categories have been subdivided into three metro and six nonmetro groupings, resulting in a nine-part county codification. The codes allow researchers working with data to break such data into finer residential groups beyond a simple metro-nonmetro dichotomy, particularly for the analysis of trends in nonmetro areas that may be related to degree of rurality and metro proximity.
|1||Counties in metro areas of 1 million population or more|
|2||Counties in metro areas of 250,000 to 1 million population|
|3||Counties in metro areas of fewer than 250,000 population|
|4||Urban population of 20,000 or more, adjacent to a metro area|
|5||Urban population of 20,000 or more, not adjacent to a metro area|
|6||Urban population of 2,500 to 19,999, adjacent to a metro area|
|7||Urban population of 2,500 to 19,999, not adjacent to a metro area|
|8||Completely rural or less than 2,500 urban population, adjacent to a metro area|
|9||Completely rural or less than 2,500 urban population, not adjacent to a metro area|