Code for the county of the patient's residence at the time the tumor was diagnosed is a derived (geocoded) variable based on Census Boundary files from 2000 Decennial Census.
This code should be used for county and county-based (such as CHSDA) rates and analysis for all cases diagnosed in 2000-2009.
Census tracts are areas geographically nested within counties and designated with a 6-digit number code. This 6-digit code is commonly repeated within a state in different counties. Census tract numbers are only unique when paired with the state and the county. Therefore, a tract cannot be accurately identified without knowing the county. Example from Massachusetts: Rural Franklin County contains a tract 040600 with 2010 population 4,612 people. Urban Suffolk County contains a tract 040600 with 2,444 people. The county must be known in order to distinguish between the two tract codes. Because we historically used a single variable for county at diagnosis [90], correct tract codes were frequently paired with the wrong county due to incorrect county assignment during abstracting or a change of county over time. Also, some variables, such as the Census Tr Poverty Indicatr [145] require the use of the decennial Census County codes closest to year of diagnosis and not the decade of year of diagnosis. Using a single county at diagnosis, and using the reported versus geocoded data, may result in erroneous assignment of geographic location as well as invalid links with census data (i.e., population, poverty category, urban/rural designation).
Instructions for Coding
- This variable is generated through the process of geocoding either during abstracting or at the central registry level.
- It is recommended that all cases diagnosed through 2009 have a geocoded County at Diagnosis 2000.
- At a minimum, all cases diagnosed through 1996-2009 should have a geocoded County at Diagnosis 2000. Cases diagnosed 1996-1999 must have both County at Diagnosis 1990 and County at Diagnosis 2000 codes for proper assignment of the Census Tract Poverty Indicator [145]. Cases diagnosed 2006-2009 must have both County at Diagnosis 2000 and County at Diagnosis 2010 codes for proper assignment of the Census Tract Poverty Indicator [145].
- If the patient has multiple tumors, geocoded county may be different for each tumor.
- Do not update this item if the patient’s county of residence changes. Store updated address information in the affiliated current address data items. Only update based on improved information on the residential address at time of diagnosis. For instance, it is appropriate to correct a county during manual geocoding or a consolidation process.
- PO Box address information should not be used to geocode this data item except in the infrequent case when no other address information is available.
- Detailed standards have not been set for Canadian provinces/territories. Use code 998 for Canadian residents.
- Blank "Not geocoded" is allowable for cases diagnosed before 1995 and after 2009. However, it is recommended to have all cases geocoded to a 2000 Census County to allow for both retrospective and cross-sectional analyses.
