Binge alcohol use among women of childbearing age is derived from the Behavioral Risk Factor Surveillance Survey (BRFSS), which is a health survey conducted by 50 states, 3 territories, and the District of Columbia, and is the primary source of information on health-related behaviors of Americans. Questions are related to chronic diseases, injuries, and infectious diseases that can be prevented. States use standard procedures to collect data through a series of monthly telephone interviews with adults. The BRFSS questionnaire is developed jointly by Centers for Disease Control and Prevention and state health departments and includes five sections. Alcohol use is part of a rotating core of questions asked every other year.
Methodological changes to the BRFSS in 2011 have affected the trends in prevalence estimates and they are not comparable to earlier years. The changes include the addition of cellular phones and improvements in the statistical weighting methods. More info can be found on the CDC Web site.
The calculation for the BRFSS binge drinking indicator is performed by the March of Dimes Perinatal Data Center, and includes the percent of women of childbearing age (18-44 years) who engage in binge alcohol use. Binge alcohol use is defined as having five or more drinks on at least one occasion during the past month. Beginning in 2006, binge alcohol use is defined as having four or more drinks on at least one occasion during the past month. Prior to 2006, binge alcohol use is defined as having five or more drinks on at least one occasion during the past month. US rate is the median of states which reported that year. More background can be found at the BRFSS Web site.