About Adult Self-Reported Lifetime and Current Asthma Prevalence
Behavioral Risk Factor Surveillance System (BRFSS) - 2005
In 2005, the BRFSS survey was conducted in all 50 states, the District of Colombia and in two US territories (Puerto Rico and the Virgin Islands). Guam did not collect any data. Due to hurricane season, Mississippi did not complete interviews in September, and Louisiana did not collect data from September through December. Puerto Rico did not collect data in March and the U.S. Virgin Islands did not collect data in July, October and November. In each area where interviews are conducted, respondents are randomly selected from noninstitutionalized civilian adults (18 years of age or older) living in households with a telephone. Asthma prevalence data are produced from the responses to two asthma questions on the year 2005 BRFSS Core Questionnaire.
Lifetime asthma: Question number 9.1
Have you ever been told by a doctor, nurse, or other health professional that you had asthma?
Current asthma: Question number 9.2
If the response to 9.1 was Yes, then question 9.2 was asked: Do you still have asthma?
BRFSS Survey Analyses
The BRFSS 2005 survey data file was used to analyze lifetime and current asthma prevalence by selected sociodemographic groups. Prevalence and standard error estimates were calculated using SUDAAN Release 9.0.1 (Research Triangle Institute, P.O. Box 12194, Research Triangle Park, NC 27709).
Number of people affected was estimated by multiplying the prevalence rate against the US or New York State population in that particular subgroup.
The 95% Confidence Intervals(CI) were calculated using the following formula:
- Lower 95% Confidence Interval = % prevalence – t(sep)
- Upper 95% Confidence Interval = % prevalence + t(sep)
Where sep is the standard error of the prevalence percent and t equals the z distribution value of 1.96 for state level prevalence in the Table titled "Overall Adult Asthma Prevalence in The US and New York State - 2005 BRFSS ". For other tables with smaller sample sizes due to the use of demographic subcategories, the exact value from the t distribution appropriate to the sample size for the percent prevalence was used instead of the approximate z-value of 1.96. Because of the use of the more exact t-value, 95% Confidence Intervals in the tables may differ slightly from those presented in other representations of these data.
Subgroup tables are based on data analyzed by the following variables:
- Gender: Male and Female
- Age Group: 18-24, 25-34, 35-44, 45-54, 55-64, and 65+
- Race: White, Black, Other, and Multi Race
- Race/Ethnicity:White NH(non-Hispanic), Black NH, Other NH, Multirace NH, and Hispanic
- Education: HS Nongrad(High School non-Graduate), HS Grad, Some Coll(College), and Coll Grad
- Income: $0-$14,999, $15,000-$24,999, $25,000-$49,999, $50,000-$74,999, and $75,000+
Note: The asthma prevalence data presented were extracted from the The Centers for Disease Control and Prevention (CDC) Asthma Data: Prevalence Tables and Maps website. For more technical information, please visit 2005 Asthma BRFSS Technical Information, CDC website.