Glossary of terms
Each term has one meaning on this site. Where CDC or the Census Bureau publishes words for the term, the entry shows them as a quotation and names the page.
- PLACES
PLACES is the project of CDC that publishes health estimates for counties, places, census tracts and ZIP Code Tabulation Areas.
The site shows the estimates for counties, places and ZIP Code Tabulation Areas. It shows none for census tracts.
PLACES provides health and health-related data using small area estimation for counties, incorporated and census designated places, census tracts, and ZIP Code Tabulation Areas (ZCTAs) across the United States.
Centers for Disease Control and Prevention, About PLACES: Local Data for Better Health (page dated 7 Dec 2025)- BRFSS
BRFSS is the telephone survey of CDC that the PLACES model uses. The letters stand for Behavioral Risk Factor Surveillance System.
Each PLACES release uses a BRFSS year for each measure. The site shows the BRFSS year beside the release year.
The Behavioral Risk Factor Surveillance System (BRFSS) is the nation’s premier system of health-related telephone surveys that collect state data about US residents regarding their health-related risk behaviors, chronic health conditions, health-care access, and use of preventive services.
Centers for Disease Control and Prevention, About BRFSS (page dated 11 Sep 2024)- Measure
A measure is one condition, behavior, service, disability, health status or social need that PLACES estimates. The site shows every measure that PLACES publishes.
Each measure page quotes the text and the definition of CDC.
- Adults
Adults are people aged 18 years and older. PLACES estimates the share of the adults of an area. Some measures are about a part of the adults, for example women aged 50 to 74.
Because we rely on the Behavioral Risk Factor Surveillance System (BRFSS), which only surveys adults aged ≥18 years, we only compute estimates for that population.
Centers for Disease Control and Prevention, PLACES Frequently Asked Questions (page dated 11 Dec 2025)- Prevalence
Prevalence is the share of a group of people that has a condition or does a behavior at one time. The site writes it as a percent.
- Model-based estimate
A model-based estimate is a figure that a statistical model gives. Nobody counted the people of the area.
A model-based estimate is for the adults of an area. It says nothing about one person.
Because these are modeled and not direct estimates, the data should not be used for ranking the overall health of any county, place, census tract, or ZCTA.
Centers for Disease Control and Prevention, PLACES Frequently Asked Questions (page dated 11 Dec 2025)The estimates for local areas are the statistically expected prevalence of the risk factor, health outcome, or preventive service use, based on the associations observed through the overall model.
Centers for Disease Control and Prevention, PLACES Frequently Asked Questions (page dated 11 Dec 2025)- Small area estimation
Small area estimation is a way to estimate a figure for an area that has too few survey answers. CDC uses a model that links the answers of a national survey to the people of each area.
A small area has a wide confidence interval.
PLACES uses a multilevel regression and poststratification (MRP) method to generate estimates of each measure at the county, place (incorporated and census designated), census tract, and ZIP Code Tabulation Area (ZCTA) levels for adults ≥18 years in the United States.
Centers for Disease Control and Prevention, PLACES Methodology (page dated 7 Dec 2025)The smaller the areas are, the broader the confidence intervals of an estimate will be.
Centers for Disease Control and Prevention, PLACES Frequently Asked Questions (page dated 11 Dec 2025)- Crude prevalence
Crude prevalence is the estimated share of all adults of the area. It does not take the ages of the adults into account.
The site shows crude prevalence first. A ZIP Code has only crude prevalence.
Age-adjusted estimates are only available at the county and place-level.
Centers for Disease Control and Prevention, PLACES Frequently Asked Questions (page dated 11 Dec 2025)- Age-adjusted prevalence
Age-adjusted prevalence is the share that an area would have if its adults had the age mix of the 2000 US standard population.
It helps to compare areas with different age mixes. CDC publishes it for counties and places only.
Finally, age-adjusted estimates that adjust for potential differences in the age-distribution across geographic units can be used for county- and place-level comparisons.
Centers for Disease Control and Prevention, PLACES Frequently Asked Questions (page dated 11 Dec 2025)- 95% confidence interval
The 95% confidence interval is the range that the model gives for an estimate. The site draws it as a band around the bar of the estimate.
A wide band means that the model is less sure of the estimate.
Monte Carlo simulation is used to generate 1,000 simulated datasets for the point estimate, the final estimates are reported as the mean and 95% confidence interval (the 2.5th, 97.5th percentiles) over 1,000 draws.
Centers for Disease Control and Prevention, PLACES Methodology (page dated 7 Dec 2025)- Higher, lower and similar
These words compare two estimates that both have a published interval. The estimate is higher when its whole interval is above the other interval. It is lower when its whole interval is below the other interval.
The estimate is similar when the two intervals overlap. The site uses no other word for a difference between two estimates.
- Above, below and in line
These words compare an estimate with a state figure, which has no interval. The estimate is above the state figure when its whole interval is above it. It is below when its whole interval is below it.
The estimate is in line with the state figure when the interval includes it.
- Release
A release is one publication of the PLACES data. Each release has a year and a date on which CDC updated the data.
The site keeps the figures of every release it has read. It shows the figures of each release as a separate record.
PLACES data are updated on an annual basis.
Centers for Disease Control and Prevention, PLACES Frequently Asked Questions (page dated 11 Dec 2025)- ZIP Code Tabulation Area (ZCTA)
A ZCTA is an area that the Census Bureau makes to approximate the area of a postal ZIP Code. PLACES estimates ZCTAs.
The site says ZIP Code for a ZCTA. A ZCTA and a postal ZIP Code can differ.
ZIP Code Tabulation Areas (ZCTAs) are approximate area representations of U.S. Postal Service (USPS) five-digit Zonal Improvement Plan (ZIP) Code service routes that the Census Bureau creates using whole blocks to present statistical data from censuses and surveys.
US Census Bureau, Glossary of geography terms (page dated 8 Sep 2026)Usually census ZCTA can be viewed as equivalent to postal ZIP Code, but be aware that postal ZIP Code changes over time whereas the census ZCTA remains the same for 10 years.
Centers for Disease Control and Prevention, PLACES Frequently Asked Questions (page dated 11 Dec 2025)- Census place
A census place is a city, town, village or borough, or a settled area that has a name but no town government. The Census Bureau calls the second kind a census designated place.
The site says place for both kinds.
An incorporated place usually is a city, town, village, or borough, but can have other legal descriptions.
US Census Bureau, Glossary of geography terms (page dated 8 Sep 2026)Census Designated Places (CDPs) are the statistical counterparts of incorporated places, and 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.
US Census Bureau, Glossary of geography terms (page dated 8 Sep 2026)- County equivalent
A county equivalent is an area that the Census Bureau treats as a county for data. Examples are a parish in Louisiana, a borough in Alaska, an independent city in Virginia and a planning region in Connecticut.
The site gives each one its legal name from the Census Bureau.
The primary legal divisions of most states are termed counties. In Louisiana, these divisions are known as parishes.
US Census Bureau, Glossary of geography terms (page dated 8 Sep 2026)In Alaska, which has no counties, the equivalent entities are the organized boroughs, city and boroughs, municipalities, and census areas; the latter of which are delineated cooperatively for statistical purposes by the State of Alaska and the Census Bureau.
US Census Bureau, Glossary of geography terms (page dated 8 Sep 2026)In four states (Maryland, Missouri, Nevada, and Virginia), there are one or more incorporated places that are independent of any county organization and, thus, constitute primary divisions of their states. These incorporated places are known as independent cities and are treated as equivalent entities for purposes of data presentation.
US Census Bureau, Glossary of geography terms (page dated 8 Sep 2026)- Site aggregate
A site aggregate is a figure that this site computes. CDC publishes no state figure. The site computes each state figure as a mean of the county estimates, weighted by the number of adults.
A site aggregate has no confidence interval. The site marks it with the words "(site aggregate)".
- Health outcomes
A CDC category of measures about conditions and diseases, for example diabetes and asthma.
The PLACES Health Outcomes data capture estimated prevalence for various chronic disease conditions, from asthma to diabetes, heart disease, cancer, and depression (among many others).
Centers for Disease Control and Prevention, PLACES measure definitions: Health Outcomes (page dated 29 Oct 2024)- Prevention
A CDC category of measures about preventive services, for example screening and checkups.
The PLACES Prevention data capture the use of key preventive health practices and services, such as cancer screenings and vaccinations.
Centers for Disease Control and Prevention, PLACES measure definitions: Prevention (page dated 11 Dec 2025)- Health risk behaviors
A CDC category of measures about behaviors that pose a risk to health, for example smoking and binge drinking.
The PLACES Health Risk Behaviors data capture estimated prevalence for various U.S. adult behaviors that pose a risk to health, from binge drinking to smoking, lack of physical inactivity, and short sleep duration.
Centers for Disease Control and Prevention, PLACES measure definitions: Health Risk Behaviors (page dated 29 Oct 2024)- Disability
A CDC category of measures about reported disabilities, for example hearing and mobility.
PLACES measure types capture the prevalence of reported disabilities among U.S. populations at four geographic levels.
Centers for Disease Control and Prevention, PLACES measure definitions: Disability (page dated 29 Oct 2024)- Health status
A CDC category of measures about reported physical and mental health.
The PLACES Health Status data capture the prevalence of self-reported physical and mental health.
Centers for Disease Control and Prevention, PLACES measure definitions: Health Status (page dated 29 Oct 2024)A CDC category of measures about needs such as food, housing and transportation. CDC publishes these measures only for states that ran the optional survey module.
The PLACES Health-Related Social Needs data capture 7 key factors such as food and housing insecurity, transportation barriers, social isolation, and lack of health insurance, which can affect health outcomes.
Centers for Disease Control and Prevention, PLACES measure definitions: Health-Related Social Needs (page dated 7 Dec 2025)
The site read the quotations on . The methodology shows how the site uses each term.
Last checked against the CDC pages: