Adapting a USPS Tool to Validate Patient Addresses

Wisconsin Cancer Reporting System

The Address Validation and Standardization Program (AVS) is a tool that contains United States Postal Service (USPS) standardized addresses for all valid street addresses in a geographic area such as the state of Wisconsin. The user enters any part of an address (street number, street name, city, county, or ZIP Code), and the resulting list contains all matches based on the data entered with the correct street format, city name (aliases provided for review), county Federal Information Processing Standard (FIPS) code, nine-digit ZIP Code, and state. The original SQL-based application was written using Visual Studio.NET 2005. The code is open, free, and may be adapted easily for other platforms, programming languages, and databases.

The AVS program was developed in 2007. The online version was developed in 2008 and featured in a presentation at CDC's Public Health Information Network (PHIN) conference in August 2009 titled "Free, Fast, Flexible and Fit for First-Class GIS: Open-Source USPS Address Validation/Standardization QED." Updates are incorporated bi-monthly from USPS.

Accurate census tract/block and residential point locations (latitude and longitude) often are required for cancer incidence and mortality spatial analysis methods. However, the address data from cancer abstracts often is submitted in a non-standardized format and its interpretation by geocoding software programs often produces false negative (un-codeable) and false positive auto-geocoding output. Cancer reporters do not have access to the USPS database to validate addresses on all cases prior to state submission. This tool provides abstractors with a quick and easy way to obtain valid patient addresses in official USPS format that can be copied and pasted in their cancer abstracting software programs. The USPS standardized address format is the basis for most geocoding software programs; thus, this tool proactively reduces geocoding errors as addresses are standardized prior to submission to the state registry where data geocoding occurs.

WCRS staff uses this application to correct incoming address errors from the approximately 2,150 annual data submissions (based on a Wisconsin-specific edit created to check for valid ZIP Code, county, and city/town/village combinations). Last year, WCRS staff corrected 4,373 address errors using this tool, and it is also used successfully in some Wisconsin reporting facilities, other state cancer registries and Vital Records offices, and non-Wisconsin reporting facilities.

Advantages of using this tool include—

• An increased proportion of case addresses will be valid and with standard USPS content.
• Automated geocoding errors will be reduced.
• Registry data will be more accurate and available for spatial analysis.