How data are collected: The Behavioral Risk Factor Surveillance System ( BRFSS) is a state-based computer-assisted telephone interview survey. The collection process uses uniform guidelines and a standard questionnaire. In collaboration with other state health departments, the Centers for Diseaase Control and Prevention, and other department programs, a survey instrument is developed. Rhode Island contracts with a vendor, ICF International, to conduct the telephone interviews. The survey is administered as a random-digit dial telephone survey of non-institutionalized people age 18 or older. Telephone numbers are selected at random. Once a household is reached, one adult within a household is randomly selected for the interview. Calls are made throughout each month. The data that are generated from the interviews are transmitted to CDC for editing, processing, weighting, and analysis. Once data sets are finalized and weighted, data are "aggregated"; the data are analyzed by categorical groups (individual responses are not reported).
The survey began as a landline telephone survey. Due to increases in cell phone use, a cell phone survey was piloted in 2009. In 2011, data from adult cell phone-only users were added to data from landline interviews. Additionally, the Centers for Disease Control and Prevention began weighting Behavioral Risk Factor Surveillance System data using a new methodology referred to as “raking”. These changes improve the overall representativeness of the BRFSS data. However, the new raking methodology precludes any trending of data from previous years (2010 and earlier data can not be compared to 2011 and later data).