BRFSS County Estimates
County-level BRFSS estimates are calculated using the annual state-level BRFSS survey data.
Methodology for County-Level Estimates
Telephone numbers and zip codes are used to determine the number of responses to the state survey by county. Since the sample size for each county is based on telephone numbers, each county will be represented roughly in proportion to the number of residential telephone lines in that county. This results in wide variations in the number of interviews from each county. For example, Pulaski County—the largest in the state—had 660 complete interviews in 2005. On the other end, Lee County, which is much smaller, had only 18 interviews completed—too small for a reliable estimate. There are two ways to address this issue: 1) combine data for multiple years, or 2) combine data for adjacent counties. The Center for Health Statistics and epidemiologists at ADH decided to use data for single years and combine the data from adjacent counties to get enough interviews to develop a reliable estimate. This method is used for all counties. Individual weights are developed for each county, and a SAS statistical analysis program is used to calculate the estimates for health risk factors for each of the counties in the state.
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