Emergency Room Visit Definitions

• Mapping Units
• Visible Layers
• Base Layers
• Definitions
• Map Tools

Presentation Information

• All numbers and rates pertain to the place of residence (not occurrence).
• If an Age group, Race, Sex, Ethnicity or Education Level are chosen, all rates/percentages include only the choices in both the numerator and denominator.
• Maps are used to emphasize the spatial distribution of one or more geographic attributes or variables. This site generates choropleth maps as thematic maps in which the geographies are shaded different colors to represent different magnitudes of a variable.
• The map projection is Lambert Conformal Conic.

Confidentiality rule:

Numbers based on 0-4 events are classified as a separate static class when a sub-county level geography (Census Tract or County Commission District) is chosen. This, in addition to offering only non-overlapping 5-year aggregates is done to assure confidentiality.

Not Reportable

At the County level or higher rates (and percents) based on 1-4 events are not reported due to statistical reliability reasons. At sub-county level (Census Tract or County Commission District), rates and percents based on 0-4 are not reported. This assures confidentiality.

Sex-Specific rates

PLEASE NOTE: Unless a sex is specifically selected, Breast, Ovarian, Cervical, Uterine and Prostate and Testes cancers will have both males and females in the numerator and denominator. Note that usually (e.g. as reported in the Vital Statistics Report), Breast, Ovarian, Cervical and Uterine have only females in both the numerator and denominator, while Prostate and Testis have only males in both the numerator and denominator.

Trendable Maps

Trendable maps are a series of choropleth maps showing change in spatial distribution of data in a selected area over selected period of time. Trendable maps share the same data class breaks which allows easy comparison between each map in the series.

Mapping Units:

• County to create a map of a selected geography: counties, Public Health District(s) or Perinatal Region(s); or
• Public Health District to create a map of the state by the 18 Public Health Districts; or
• Perinatal Region to create a map of the state by the 6 Perinatal Regions; or   
• County Commission District or Census Tract to create a map of a selected geography: counties, Public Health District(s) or Perinatal Region(s)

Visible Layers:

Census Tracts

Census Tracts are small, relatively permanent statistical subdivisions of a county or equivalent entity that are updated by local participants prior to each decennial census.

Census tracts generally have a population size between 1,200 and 8,000 people.  A census tract usually covers a contiguous area; however, the spatial size of census tracts varies widely depending on the density of settlement.  Census tract boundaries are delineated with the intention of being maintained over a long time so that statistical comparisons can be made from census to census.  Census tracts occasionally are split due to population growth or merged as a result of substantial population decline.

Census tract boundaries generally follow visible and identifiable features.  They may follow nonvisible legal boundaries, such as minor civil division (MCD) or incorporated place boundaries in some states and situations, to allow for census-tract-to-governmental-unit relationships where the governmental boundaries tend to remain unchanged between censuses.  State and county boundaries always are census tract boundaries in the standard census geographic hierarchy. Reference Source: U.S. Commerce Department, United States Census Bureau, accessed July 2011

Cities/Towns

A mix of both incorporated places (legal entities) and census designated places or CDPs (statistical entities). An incorporated place is established to provide governmental functions for a concentration of people. Places always nest within a state, but may extend across county and county subdivision boundaries. An incorporated place usually is a city, town, village, or borough, but can have other legal descriptions. CDPs are delineated to provide data for settled concentrations of population that are identifiable by name, but are not legally incorporated under the laws of the state in which they are located. Each dot represents the centroid of the geographical area of the city/town. Click on the dot to get the city or town name. Reference Source: U.S. Census, January 1, 2013

County Commission Districts

For more information, see http://www.accg.org/. The districts were established in 2014, and were obtained from the Association of County Commissioners of Georgia (ACCG). Further processing was performed by the Office of Health Indicators for Planning (OHIP) of the Georgia Department of Public Health. History and role: In 1868 the state began creating the position of county commissioner to administer the general operations of the county. Today every county has a commissioner; many have a board of commissioners (BOC). As part of general county operations, the BOC must finance county programs. A BOC has the power to adopt ordinances, resolutions, or regulations relating to county property, county affairs, and the operation of local government (http://www.georgiaencyclopedia.org/nge/Article.jsp?id=h-589 ).

GA House Districts

Electoral districts from which State Representatives are elected. The Georgia Constitution requires not less than 180 Representatives apportioned by population from representative districts. Layer Source: https://www.legis.ga.gov/, Adopted 2021 – Effective for 2022 Elections.

GA Senate Districts

Electoral districts from which State Senators are elected. The Georgia Constitution limits the number to not more than 56 single member districts. Senate districts are apportioned based on population. Layer Source: https://www.legis.ga.gov/, Adopted 2021 – Effective for 2022 Elections.

Hospitals

Hospitals are the non-Federal acute-care inpatient medical facilities in Georgia. Click on the symbol to get the name. Reference Source: Georgia Hospital Association, 2021

Interstates

Interstates are the freeways that are part of the Interstate Highway System in Georgia. The Interstate Highway System connects major cities within the United States. Click on the line to get the Interstate number. Layer Source: Esri, March 1, 2012

Major Roads

Major roads are a combination of both federal and state highways connecting cities and towns. Click on the line to get the route number. Layer Source: Esri, March 1, 2012

Perinatal Regions

The Perinatal Regions were established by the Department of Public Health in cooperation with the six teaching hospitals located in Atlanta, Albany, Augusta, Columbus, Macon and Savannah. The Regions reflect the hospital referral patterns for high risk pregnant women and newborns Each of the six hospitals has a Regional Perinatal Center which has contracts with the state and receives funding to care for high risk pregnant women and infants as well as to train staff from other hospitals in perinatal care especially for high risk patients. Reference Source: Georgia Department of Public Health, March 2005

ZIP Code

Established by the U.S. Postal Service for distribution of mail. Zip codes do not generally respect political boundaries or census areas such as tracts. Zip codes usually do not have clearly identifiable boundaries, often serve a continually changing area, are changed periodically to meet postal requirements, and do not cover all land area in the U.S. Layer Source: Esri, June 1, 2020

Base Layers:

Base layers are background information to provide contextual references for local-level maps. They are especially suited for tract-level maps and give real-world reference to maps you create in OASIS. There are three toggle-able (on/off) base layers:

Demographic Clusters

Demographic Clusters refer to the socioeconomic status classifications created by OHIP, and are at the census block-group level. More information here: https://oasis.state.ga.us/gis/demographiccluster/DemoClusters2011.htm

Aerial Photography

Aerial Photography refers to ESRI's World Imagery.

Socioeconomic Vulnerability

Socioeconomic Vulnerability refers to the socioeconomic status domain/subset of the CDC’s Social Vulnerability Index (SVI), and is at the census tract level. Socioeconomic vulnerability ranks tracts within the state on 4 factors: below poverty, unemployed, income, and no high school diploma. Percentile ranking values range from 0 to 1, with higher values indicating greater vulnerability/lower socioeconomic status. Quartiles were used to create class breaks. For more information see https://www.atsdr.cdc.gov/placeandhealth/svi/index.html. For data dictionary click here.

Street Map

Street Map refers to ESRI's World Street Map with street-level data for North America.

Data Classification Methods:

Natural Breaks (Jenks)

This method minimizes within-class variance and maximizes between-class variance in an iterative series of calculations. This method seeks to partition data into classes based on natural groups in the data distribution. Natural breaks occur in the histogram at the low points of valleys. Breaks are assigned in the order of the size of the valleys, with the largest valley being assigned the first natural break.

George F. Jenks is considered a pioneer in GIS educational programs. Through an award from the Fund for Advancement of Science, Jenks identified four key objectives for cartographic training. Robert McMaster and Susanna McMaster; A History of Twentieth-Century American Academic Cartography

Source: Brewer and Pickle. Evaluation of Methods for Classifying Epidemiological Data on Choropleth Maps in a Series. Annals of the Association of American Geographers, 92(4), 2002, pp. 662-681.

Quantiles

• Data values for each enumeration unit (e.g. county or census tract) are ranked from lowest to highest.
• The total number of values is divided by the number of classes specified by the user to determine how many values each class will contain. The object is to obtain a roughly equal number of data values within each class. For example, if you have 100 census tracts and the tract data values are to be classed into 5 classes, each class will have 20 values (100/5 = 20).
• In some cases, an equal number of values will not be placed into each class. For instance, if there are an odd number of enumeration units some classes will have a larger number of data values than others. If data values for the 159 counties of Georgia are divided into 4 classes, then some classes might have 39 data values while others have 40. In addition, identical data values are maintained within the same classes. Continuing the Georgia county example, if 45 of the lowest data values are 0, then the lowest class will have 45 data values all with a value of 0.

The quantiles method of classification is provided because:

• Quantiles classification is one of the simplest methods of classification and is easy to understand and interpret.
• Classes are usually centered on the median, a measure of central tendency, and "they group enumeration units above and below the median into classes with equal frequencies regardless of their values." This makes maps easier to compare with one another.
• Many health-related measures are distributed normally (i.e. a large number of values falling near the middle of the data range with a smaller number of values on the low and high ends of the data range) making quantiles classification a logical classification method.

Source: Brewer and Pickle. Evaluation of Methods for Classifying Epidemiological Data on Choropleth Maps in a Series. Annals of the Association of American Geographers, 92(4), 2002, pp. 662-681.

Definitions:

Age

Ages are presented by Detailed Age Groups, Lifestages and Single Year of Age which is created by the Department of Public Health, OHIP. Also, note that selecting "all ages" will supercede any start and end age selection. Uncheck "all ages" to make an age-specific selection.

Age-Adjusted Rates

A weighted average of the age-specific rates, where the weights are the proportions of persons in the corresponding age groups of a standard population. The calculation of an Age-Adjusted Rate uses the year 2000 U.S. standard million. Benefit: Controls for differences in age structure so that observed differences in rates across areas such as counties are not due solely to differences in the proportion of people in different age groups in different areas. Rates are per 100,000 population.

Cause of Emergency Room Visit

Causes are based on the principal diagnosis, except where the principal diagnosis is an injury code. All discharges/ER visits having ICD-9-CM external causes (injuries) are assigned their appropriate External Cause of Injury Code (E-Code) in accordance with STIPDA (State and Territorial Injury Prevention Directors Association) 2003 guidelines. The standards can be found at: http://www.safestates.org/.

Similarly, all hospital discharges/ER visits having ICD-10-CM causes are based on the principal diagnosis, except where the principal diagnosis is an Injury code. If so, the Discharge/ER visit is assigned the appropriate External Cause of Injury in accordance with Safe States guidelines. See OASIS CAUSE LEVELS.

Data Classes

Also referred to as "class breaks" or groupings of data.

Deduplicated ER Visits

The number of ER patients discharged alive from non-Federal acute-care facilities (hospitals) for illness. Only ER visits of Georgia residents who were seen in a Georgia facility are included. Persons are counted only once if readmitted for the same chronic condition during a calendar year. Deduplicated ER visits also exclude people discharged dead, healthy newborn infants, and healthy mothers giving birth to newborn infants. Since the number and rate are derived only from ER visits, they do not include all existing cases (prevalence) or new cases (incidence) among residents of Georgia.

ER Visits

The number of emergency room visits to non-Federal acute care inpatient facilities. Only discharges of Georgia residents who were seen in a Georgia facility are included. Persons can be counted more than once if readmitted. Visits include people both living and who have died, but not those admitted as an inpatient to a hospital. Since the number and rate are derived only from ER visits, they do not include all existing cases (prevalence) or new cases (incidence) among residents of Georgia. ER Visits are reported by date of discharge, not admitting date.

ER Visit Rate

Formula = [Number of ER Visits / Population] * 100,000. Rates that use Census Population Estimates in the denominator are unable to be calculated when the selected population is Unknown.

Ethnicity

Hispanic or Latino includes persons of Mexican, Puerto Rican, Cuban, South or Central American, or other Spanish culture or origin, regardless of race. Non-Hispanic + Hispanic may not equal the total number of events due to persons of unknown ethnicity.

Georgia Rankable Cause Groups

Georgia Rankable Causes are unique to Georgia and were developed to represent mutually exclusive groups of ICD codes that are intended to share common etiology and/or common intervention.

International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM)

A statistical classification system, in use since 1979, that arranges diseases and injuries into groups according to established criteria. It is used to improve comparability of cause of death statistics reported by different governmental entities. Most ICD-9-CM codes are numeric and consist of three, four or five numbers and a description. The codes are revised approximately every 10 years by the World Health Organization and annual updates are published by the Health Care Financing Administration (HCFA), now the Center for Medicare, Medicaid Services.

International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) vs. ICD10

The National Center for Health Statistics (NCHS), the Federal agency responsible for use of the International Statistical Classification of Diseases and Related Health Problems, 10th revision (ICD-10) in the United States, has developed a clinical modification (CM) of the classification for morbidity (hospital and ER data) purposes. The ICD-10 is used to code and classify mortality data from death certificates, having replaced ICD-9 for this purpose as of January 1, 1999. ICD-10-CM is the replacement for ICD-9-CM, effective October 1, 2015 in discharge and ER data.

The ICD-10 is copyrighted by the World Health Organization (WHO). WHO has authorized the development of an adaptation of ICD-10 for use in the United States (ICD-10-CM). All modifications to the ICD-10 must conform to WHO conventions for the ICD. https://www.cdc.gov/nchs/icd/icd10cm.htm

Lifestages

An age year grouping methodology based upon predictable mortality. Georgia uses the following Lifestages: <1 Infancy, 1-4 Early Childhood, 5-12 Later Childhood, 13-19 Adolescence, 20-29 Early Adulthood, 30-44 Young Adulthood, 45-59 Middle Adulthood, 60-74 Late Adulthood, and 75+ Older Adulthood. The highest value for age is 120 years.

Payor

Payor is the primary entity responsible for payment of services. Values for Payor include:

• Medicaid, based on Title XIX of the Social Security Act, is a Federal-State matching entitlement program that pays for medical assistance for certain vulnerable and needy individuals and families with low incomes and resources;
• PeachCare for Kids (Georgia's State Child Health Insurance Program (SCHIP)) is a program that provides comprehensive health care insurance for children through the age of 18 who do not qualify for Medicaid and live in households with incomes at or below the federal poverty level;
• Medicare is a health insurance program for people age 65 or older, some disabled people under age 65, and people of all ages with End-Stage Renal Disease (permanent kidney failure treated with dialysis or a transplant);
• Private Insurance includes Blue Cross / Blue Shield, HMO/Managed Care, Commercial Insurance, Other non-specified Managed Care, PPO (Preferred Provider Organization), POS (Point of Service Provider),State Health Benefit Plan (SHBP); and
• Self Pay includes patients with no proof of insurance, patients filing their own insurance claims, patients paying their own bills, Hill-Burton cases, charity cases, etc.; and
• Other (All other plans) and Unknown Payor.

Percent of ER Visits by Cause

The percent of Emergency Room Visits or deduplicated Emergency Room Visits from a selected cause(s) in selected geography(ies) is of all Emergency Room Visits or deduplicated Emergency Room Visits in the selected geography(ies). If a cause is not selected the user will be prompted to select a cause.

Formula = [Number of ER Visits from Cause / Total number of ER Visits] * 100. Example of what this can tell you: "Of all ER Visits, paid for by Medicaid, what percentage are from diabetes?"

Race

Per the Federal Office of Management and Budget, Directive 15 (1997),

• White is a person having origins in any of the original peoples of Europe, the Middle East or North Africa;
• Black or African-American is a person having origins in any of the black racial groups of Africa;
• Asian is a person having origins in any of the original peoples of the Far East, Southeast Asia, or the Indian subcontinent including for example, Cambodia, China, India, Japan, Korea, Malaysia, Pakistan, the Philippine Islands, Thailand and Vietnam;
• American Indian/Alaska Native is a person having origins in any of the original peoples of North and South America (including Central America), and who maintains tribal affiliation or community attachment;
• Native Hawaiian or Other Pacific Islander is a person having origins in any of the original peoples of Hawaii, Guam, Samoa, or other Pacific Islands;
• Multiracial is a person declaring 2 or more of these races.

Standard ER Visit Ratio / Standard ER Deduplicated Visit Ratio

Answers whether a local rate is statistically significantly different from the same rate for the State. Standard ER Visit Ratio or Standard ER Deduplicated Visit Ratio is a statistical calibrator of confidence level in the rates of populations. It is indicative whether a rate is within the "normal" range of estimated values or significantly higher/lower to such estimates. Rates are compared to those for Georgia as a whole. State rates are the standard against which local rates are compared, in order to forecast the number of likely events in a local area. It is a statistic indicating significance at the 95% confidence level.
Higher: Significantly higher ratio than expected based on the State ratio. Expected: No significant difference as compared to the State. Lower: Significantly lower ratio as compared with the State.

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V1.20 (11/9/2022)