2011 Asthma Data: BRFSS Prevalence Tables and Maps

BRFSS Sampling and Weighting Changes

The 2011 BRFSS data collection changed from a landline sample survey to a dual-mode survey, landline and cellphone. The 2011 BRFSS data reflects a change in weighting methodology (raking) and the addition of cell phone only respondents. The aggregate BRFSS combined landline and cell phone dataset is built from the landline and cell phone data for 2011 and includes data for 50 states, the District of Columbia and Puerto Rico. Guam and the Virgin Islands were not included in the initial data release because current population estimates were not available. These territories will be included after the 2010 Census estimates have been released. More information about the changes to the 2011 BRFSS can be found at the Web location: https://www.cdc.gov/surveillancepractice/reports/brfss/brfss.html

For data analysis, the 2011 BRFSS data should be considered a baseline year and are not directly comparable to previous years of data because of the changes in weighting methodology and the addition of the cell phone only respondents . Please see the BRFSS Frequently Asked Questions document for additional information: https://www.cdc.gov/surveillancepractice/reports/brfss/brfss_faqs.html