Fig. 1

BRFSS U.S. Asthma Prevalence (2007-2012). Asthma was defined as affirmative responses to questions “Have you ever had asthma?” and “Do you currently have asthma?” Never asthma was based on negative response to “Have you ever had asthma?” Respondents were at least 22 years old at the time surveyed and resided in 408 U.S. counties. No data was available for counties shaded in grey