Methodology

What to know

  • PLACES estimates chronic disease and other health-related measures at various geographic levels of the United States using a small area estimation methodology.
  • Data are derived from Behavioral Risk Factor Surveillance System data, Census population data, and American Community Survey data.
  • There are 40 measures generated using this method in 2024 release.
Graphic of people taking giant binders off shelves and analyzing data on a giant laptop with a giant magnifying glass.

Overview

The methodology described here is only for the small area estimation (SAE) approach that is used to generate PLACES estimates using:

  • Behavioral Risk Factor Surveillance System (BRFSS) data.
  • U.S. Census Bureau's American Community Survey (ACS) data.
  • Decennial population counts or annual county population estimates.

The Social determinants of Health (SDOH) measures were derived directly from ACS data and are not included in this section. See SDOH measure definitions for details.

PLACES methodology

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.

A multilevel logistic regression model is constructed for each measure. It includes some or all of the following variables based on model performance and final prediction:

  • Individual-level age, sex, race/ethnicity, and education level from CDC's BRFSS.
  • County-level percentage of adults below 150% of the federal poverty level from the 5-year ACS.
  • State- and county-level random effects.

The model is applied to annual county-level census population estimates to compute a predicted probability of having each outcome.

  • The county-level estimates are obtained by multiplying the probability by the total adult population of each county.

The model is applied to decennial 2020 (2010 for releases 2023 and before) census block-level population counts to compute a predicted probability as well.

  • The estimated prevalence can be obtained by multiplying the probability by the total adult population for each block, which can be aggregated to place, census tract, and ZCTA levels.

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.

The MRP approach is flexible by modeling nationally and predicting locally and can be used to provide modeled estimates at any geography above the census blocks (the smallest census geography).

Validation

Both internal and external validation studies showed strong/moderate correlations between model-based estimates and direct survey estimates at state, county, and place levels.

Measures

  • The 2024 PLACES release includes 40 measures, including:
    • 12 health outcomes
    • 7 prevention practices
    • 4 health risk behaviors
    • 7 disability measures
    • 3 health status measures
    • 7 health-related social needs (only for 39 states and the District of Columbia)

  • The measures capture major risk behaviors that lead to illness, suffering, and early death related to chronic diseases and conditions, as well as the conditions and diseases that are the most common, costly, and preventable of all health problems.
  • Each measure has a comprehensive definition that includes the background, significance, limitations of the indicator, data source, and limitations of the data resources.
  • Measures complement existing sets of surveillance indicators that report state, metropolitan area, and county data, including County Health Rankings and Chronic Disease Indicators.
Keep Reading: Measure Definitions

The number of measures included in PLACES has increased over time:

  • In 2023 there were 36 measures.
  • In 2021 and 2022 there were 29 measures.
  • In 2020, there were 27 measures.

More information

Further information on the PLACES approach and small area estimation methodology can be obtained from:

Keep Reading: Publications and Resources
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Content Source:
National Center for Chronic Disease Prevention and Health Promotion