About Tennessee Behavioral Risk Factor Surveillance System (TN BRFSS)
BRFSS Methodology
BRFSS is a survey meant to represent Tennessee’s adult population, so its data must be weighted, or extrapolated to the greater population of the state. While complicated and detailed, the CDC uses a variety of demographic and sampling (cluster and stratum) information to complete this process. More detail on the CDC’s weighting methodology can be found here: Weighting the BRFSS Data (cdc.gov).After BRFSS data is successfully weighted, any given respondent’s answers to the survey will represent a certain number of residents who are similar to or just like the respondent in demographics and geographic location.
A geographic region must have at least 500 respondents in order to be weighted appropriately (which is why county-level estimates cannot be created), and until the 14 Public Health Regions in Tennessee have 500 respondents in each region, the TN BRFSS will continue to utilize the state’s three Grand Divisions (west, middle, and east) as the most granular geographic variable to obtain estimates for.
The BRFSS went through a couple of methodological changes in 2011; therefore, data users should use caution when comparing any surveys from 2011 forward to any previous surveys. Please see the following CDC website for more information on the change in methodology: Change in BRFSS Methodology.
For more information on general BRFSS data collection protocol and methodology, refer to The BRFSS Data User Guide.
To find out which questions were asked for a given year, please refer to the BRFSS Matrix .
The TDH BRFSS team is happy to provide data and statistical expertise for any of your research or program needs. Please visit the data request system website to submit a data request, or contact the BRFSS Coordinator