Data Sources and Measures

The County Health Rankings team synthesizes health information from a variety of national data sources to create the Rankings. Most of the data we use are public data available at no charge. Measures based on vital statistics data, sexually transmitted disease rates, and Behavioral Risk Factor Surveillance System (BRFSS) survey data were calculated for us by staff at the National Center for Health Statistics and other units of the Centers for Disease Control and Prevention (CDC). Our health care quality measures were calculated for us by the authors of the Dartmouth Atlas of Healthcare, using Medicare claims data.

We have compiled the following summary information regarding the 2018 measures:

A brief description of each of our data sources follows.

Behavioral Risk Factor Surveillance System (BRFSS)

The Behavioral Risk Factor Surveillance System (BRFSS) is a national random digit dial (RDD) telephone survey. Data obtained from the BRFSS are representative of the total non-institutionalized population over 18 years of age living in households with a landline or cellular telephone. For the County Health Rankings, data from the BRFSS are used to measure various health behaviors and health-related quality of life (HRQOL) indicators. All data from the BRFSS were weighted by population and the HRQOL measures were age-adjusted. The Centers for Disease Control and Prevention (CDC) calculated these county-level measures and provided them to the County Health Rankings. In 2011, the methodology of the BRFSS changed; a summary of how CDC adjusted their calculations in response to those changes can be found here.

The Dartmouth Institute

Since 1996, the Dartmouth Atlas of Health Care has examined patterns of health care delivery and practice across the United States, and evaluated the quality of health care Americans receive. The research has revealed striking variations in the amount of health care you are likely to receive depending on where you live. This is true not only across states and regions, but within individual states and cities. The very large claims databases used in the Dartmouth Atlas Project come from the federal agency, the Centers for Medicare and Medicaid Services (CMS). CMS collects data for every person and provider using Medicare health insurance. Access to this data is made available for research purposes. Normally, the Dartmouth Atlas reports data by hospital service area and hospital referral region, but for the County Health Rankings, staff from the Dartmouth Institute identified and calculated a small subset of quality of care measures by county.

American Community Survey, 5-year estimates

The American Community Survey (ACS) is a nationwide survey designed to provide communities a fresh look at how they are changing. It is a critical element in the Census Bureau's re-engineered decennial census program. The ACS collects and produces population and housing information every year instead of every ten years. For the County Health Rankings, American Community Survey data are used to obtain measures of social and economic factors.

CDC Diabetes Interactive Atlas

The National Diabetes Surveillance System provides county-level estimates of obesity, physical inactivity, and diabetes. The county-level estimates for the more than 3,200 counties or county equivalents (e.g., parish, borough, municipio) in the 50 U.S. states, Puerto Rico, and the District of Columbia were developed using modern small area estimation techniques. This approach employs a statistical model that “borrows strength” in making an estimate for one county from BRFSS data collected in other counties. Bayesian multilevel modeling techniques were used to obtain these estimates.


CDC WONDER -- Wide-ranging Online Data for Epidemiologic Research -- is an easy-to-use, menu-driven system that makes the information resources of the Centers for Disease Control and Prevention (CDC) available to public health professionals and the public at large. It provides access to a wide array of public health information. The Rankings access data on mortality and air quality from the system.

Comprehensive Housing Affordability Strategy (CHAS) data

CHAS data, from the U.S. Department of Housing and Urban Development, are custom tabulated tables from the American Community Survey that inform decisions about the number of households that are in need of housing assistance.

County Business Patterns

County Business Patterns provides data on the total number of establishments, mid-March employment, first quarter and annual payroll, and number of establishments by nine employment-size classes by detailed industry for all counties in the United States and the District of Columbia.

CMS, National Provider Identification (NPI)

The NPI Registry enables you to search for a provider's National Plan & Provider Enumeration System (NPPES) information. All information produced by the NPI Registry is provided in accordance with the NPPES Data Dissemination Notice. Information in the NPI Registry is updated daily. You may run simple queries to retrieve this read-only data. For example, users may search for a provider by the NPI or Legal Business Name.

Fatality Analysis Reporting System (FARS)

FARS is a census of fatal motor vehicle crashes with a set of data files documenting all qualifying fatalities that occurred within the 50 States, the District of Columbia, and Puerto Rico since 1975. To qualify as a FARS case, the crash had to involve a motor vehicle traveling on a trafficway customarily open to the public, and must have resulted in the death of a motorist or a non-motorist within 30 days of the crash.

Federal Bureau of Investigation, Uniform Crime Reporting

The Uniform Crime Reporting (UCR) Program was conceived in 1929 by the International Association of Chiefs of Police to meet a need for reliable, uniform crime statistics for the nation. In 1930, the FBI was tasked with collecting, publishing, and archiving those statistics. Today, several annual statistical publications, such as the comprehensive Crime in the United States, are produced from data provided by nearly 17,000 law enforcement agencies across the United States. The Rankings uses data produced by this program and archived by the National Archive of Criminal Justice Data

Health Resources and Services Administration, Area Health Resource File

The Area Resource File is a collection of data from more than 50 sources, including: American Medical Association, American Hospital Association, US Census Bureau, Centers for Medicare & Medicaid Service, Bureau of Labor Statistics, and the National Center for Health Statistics.

Map the Meal Gap

Map the Meal gap analyzes the relationship between food insecurity and its determinants (poverty, unemployment, median income, etc.) at the state level, then using these data in combination with county level data, generates estimated food-insecurity rates for all individuals and for children at the county and congressional district levels. Data sources for Map the Meal Gap include: The Current Population Survey (CPS), the American Community Survey (ACS) and the Bureau of Labor Statistics (BLS).

Business Analyst, Delorme map data, ESRI and US Census Tigerline Files

The ArcGIS Business Analyst, for a fee (University of Wisconsin license), provides access to robust, integrated business intelligence, including corporate families, industries, key executives and financial data. The DeLorme Map Mart and ESRI public use GIS data provide geocoded, projected data on parks at the local, state and national level across the US. US Census Tigerline files are spatial extracts from the Census Bureau's MAF/TIGER database, containing features such as roads, railroads, rivers, as well as legal and statistical geographic areas.

National Center for Health Statistics (NCHS)

Data on deaths and births were provided by NCHS and were drawn from the National Vital Statistics System (NVSS). These data are submitted to the NVSS by the vital registration systems operated in the various jurisdictions legally responsible for the registration of vital events – births, deaths, marriages, divorces, and fetal deaths.

National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention

Data on sexually transmitted infections were provided by the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP). NCHHSTP is responsible for public health surveillance, prevention research, and programs to prevent and control human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS), other sexually transmitted diseases (STDs), viral hepatitis, and tuberculosis (TB). Center staff work in collaboration with governmental and nongovernmental partners at community, state, national, and international levels, applying well-integrated multidisciplinary programs of research, surveillance, technical assistance, and evaluation.

Safe Drinking Water Information System

The Safe Drinking Water Information System (SDWIS) contains information about public water systems and their violations of EPA's drinking water regulations, as reported to EPA by the states. These regulations establish maximum contaminant levels, treatment techniques, and monitoring and reporting requirements to ensure that water systems provide safe water to their customers.

US Census, Small Area Health Insurance Estimates

The US Census Bureau's Small Area Health Insurance Estimates (SAHIE) program produces estimates of health insurance coverage for states and all counties.

US Census, Small Area Income and Poverty Estimates

The US Census Bureau, with support from other federal agencies, created the Small Area Income and Poverty Estimates (SAIPE) program to provide more current estimates of selected income and poverty statistics than those from the most recent decennial census. Estimates are created for school districts, counties, and states. The main objective of this program is to provide updated estimates of income and poverty statistics for the administration of federal programs and the allocation of federal funds to local jurisdictions. These estimates combine data from administrative records, intercensal population estimates, and the decennial census with direct estimates from the American Community Survey to provide consistent and reliable single-year estimates.

US Department of Agriculture, Food Environment Atlas

This resource assembles food environment statistics to stimulate research on the determinants of food choices and diet quality. The Food Environment Atlas provides a spatial overview of a community’s ability to access healthy food. Data is available on store and restaurant availability, access and proximity to a grocery store, restaurant expenditures, food assistance programs, food insecurity, food price, health, and socioeconomic factors.

U.S. Department of Education (EDFacts)

EDFacts is a U.S. Department of Education (ED) initiative to govern, acquire, validate, and use high-quality elementary and secondary graduation data in education planning, policymaking, and management decision making to improve outcomes for students. EDFacts centralizes data provided by State Education Agencies at the state, school district, and school levels, and provides ED with the ability to easily analyze and report the data.