Geographic Definitions

The geographic levels available for analysis vary for each tool in the MOPHIMS MICAs and Community Data Profiles.

Statewide (Missouri)

Data for all records that list the state of residence as Missouri are included in the statewide geographic level. Records with missing or invalid data values in the county field are included in statewide totals but will not be included within any county. Therefore, the total of all counties or regions may not equal the statewide total.

County

The state of Missouri contains 114 counties and the independent City of St. Louis. The independent City of St. Louis is not contained within any county; rather, it functions as its own county and therefore is included in the county geographic level in MOPHIMS.

City

Several of the MOPHIMS MICA and Community Data Profile tools provide data for three cities: Independence, Joplin, and Kansas City. Data are prepared for these three cities because they have local health departments that are independent of the counties in which they are located.

Another geography included in the city geographic level is Eastern Jackson County, which is defined as Jackson County excluding the areas defined as Kansas City and Independence. The Jackson County Health Department serves only the Jackson County residents who do not reside within Kansas City or Independence; the Eastern Jackson County geography therefore provides data for the Jackson County Health Department service area.

City assignment varies by dataset.

  • For data from the birth and death certificates, each city is assigned a code using city limit boundaries.
  • For data from the Patient Abstract System (PAS) the following definitions are used:
    • Prior to 2005, Joplin was defined as including ZIP codes 64801 and 64804. For data from 2005 forward, Joplin is defined based on census tracts, which more closely align with Joplin city limits. MICA users may find large differences in counts/rates between 2004 and 2005 for Joplin. These differences are likely a reflection of this definitional change rather than any real changes in health patterns in the community.
    • Prior to 2011, Independence, Kansas City, and Eastern Jackson County were defined based on ZIP codes. For data from 2011 forward, Independence, Kansas City, and Eastern Jackson County are defined based on census tracts. Census tracts more closely align with city limits for these geographies as compared to ZIP codes. Some differences in counts/rates between 2010 and 2011 may be seen, however, the differences are not as large as with Joplin. 

This map of Independence/Kansas City/Eastern Jackson County by ZIP code is available to users who wish to view the pre-2011 allocation of ZIPs for the Kansas City area city geographies.

BRFSS Region

The Missouri Behavioral Risk Factor Surveillance System (BRFSS) is an annual telephone survey of adults age 18 and older that collects a range of information on health issues. For this survey, the sample size from each county, on an annual basis, is too small to make conclusive estimates by county. Therefore, the counties and St. Louis City are clustered into the following seven geographical BRFSS regions to examine sub-state level results: Kansas City Metro, St. Louis Metro, Central, Southwest, Southeast, Northwest, and Northeast. These regions are frequently used for analysis of other areas as well and have been added to most of the other tools within the MOPHIMS MICAs and Community Data Profiles.  View a map of the BRFSS Regions to see these county groupings.

LPHA Region

Missouri’s counties are divided into nine LPHA (Local Public Health Agency) Regions, which align with Missouri’s Highway Patrol Regions. The LPHA Regions are often used for emergency planning, among other purposes, and have been added to most of the MOPHIMS MICAs and Community Data Profiles. View a map of the LPHA Regions to see these county groupings.

RPC Region

Missouri is divided into 19 Regional Planning Commissions (RPCs) that were developed by the State and Regional Planning and Community Development Act in 1965. The RPCs provide a variety of services and assistance to local governments. View a map of the RPC Regions to see these county groupings.

ZIP/ZCTA

ZIP/ZCTA data are available in some MICAs but are not available in the Community Data Profiles due to small numbers. ZIP codes are utilized by the United States Postal Service (USPS) to deliver mail more efficiently. ZIP code information is collected on many health records and is often a useful tool for analyzing small areas. However, ZIP code analysis presents many challenges. ZIP codes do not align with county boundaries.  In fact, one ZIP code may stretch across multiple counties. Therefore, the sum of all ZIP code-based frequencies for a county will not match the county total. In MOPHIMS, ZIP codes are assigned to each county based on whether at least 5% of the ZIP code’s total population was contained in that particular county.

ZCTAs, or ZIP Code Tabulation Areas, were developed by the United States Census Bureau to assist in aggregating ZIP code data.

ZIP/ZCTA rates in the MOPHIMS MICAs should be used with caution. The numerator for the rate calculation is based on the ZIP code (described above), while the denominator is based on the ZCTA. This results in several limitations.

  • In many cases, the ZIP codes and ZCTAs match, but they sometimes do not align exactly. To read about the difference between ZIP codes and ZCTAs, please visit https://www.census.gov/geo/reference/zctas.html.
  • ZCTAs are not assigned for ZIP codes that have very few postal addresses, so rate calculations for those ZIP codes are not possible. Only ZIP codes that have a corresponding ZCTA are available for analysis in the MOPHIMS MICAs.
  • ZIP code boundaries can change on a continuous basis. ZCTA boundaries, however, are only updated for each decennial Census. All ZIP code rates for intercensal years use the prior decennial Census ZCTA population as the denominator. This causes multiple issues.
    • Unrealistic rates may develop during intercensal years. For example, if a ZIP code experiences large growth over the course of a decade, the rate may increase greatly over that time period because the denominator is not being updated to reflect the larger population in the geography.
      • Because it takes time to apply the boundaries assigned at the decennial census, those denominator estimates do not begin with the decennial year itself, rather they are used for the following intercensal year through the next decennial Census.
    • ZIP/ZCTA data are not comparable across decades.

Census Tract

Census tracts are small subdivisions of a county that can be used to approximate neighborhoods. Census tracts are based upon population density rather than geographic size.  Thus, if a Census tract population grows larger, the tract will be divided within its existing boundaries to maintain density. Census tracts are only updated at the decennial Census and are therefore a more stable geography than ZIP codes. However, the limitations addressed above with ZCTAs/ZIPs are still present

  • Unrealistic rates may develop during intercensal years. For example, if a census tract experiences large growth over the course of a decade, the rate for that tract may increase greatly over that time period because the denominator is not being updated to reflect the larger population in the geography.
      • Because it takes time to apply the boundaries assigned at the decennial census, those denominator estimates do not begin with the decennial year itself, rather they are used for the following intercensal year through the next decennial Census.
  • Census tract data are not comparable across decades.