The Federal Liaison Group on Asthma (FLGA) is a subcommittee of the National Asthma Education and Prevention Program (NAEPP). The FLGA is comprised of representatives from 21 federal agencies that have programmatic activities related to asthma. The FLGA meets two to three times a year to explore ways of strengthening federal coordination of asthma activities.
One of five focus areas of the FLGA is asthma data and surveillance. FLGA members acknowledge that there is confusion about recent national asthma prevalence estimates due to changes in National Health Interview Survey (NHIS) methodology in 1997. To clear up confusion among the public and policy makers, the FLGA has developed two reference documents, Asthma:
These documents are intended to facilitate an informed and consistent explanation by federal agencies for changes in the asthma numbers, and to serve as a briefing outline in preparation for interviews with the media, for public discussions, and in preparation of written materials.
The National Center for Health Statistics of the Centers for Disease Control and Prevention (CDC)--a member of the FLGA--conducts the NHIS each year to collect data for estimating asthma prevalence. Between 1997 and 2001, the changes in methodology most affecting estimates were modifications to the sampling frames, changes in wording to survey questions, and changes in the combination and sequencing of questions asked. In a given year, depending on what questions are asked, the resulting data provides estimates of period prevalence of asthma, lifetime diagnosis of asthma, asthma attack prevalence, and/or current asthma prevalence. Based on the actual questions asked from 1980 through 2001, the resulting data has provided the following prevalence estimates:
|1980 - 1996:||Period Prevalence of Asthma (used as a surrogate for current asthma)
Based on the question, "During the past 12 months, did anyone in the family have asthma? If yes, who?"
|1997 - 2000:||Lifetime Diagnosis of Asthma
Asthma Attack Prevalence
Based on the questions, "Has a doctor or other health professional ever told you that you had asthma?", followed by, ÒDuring the last 12 months have you had an episode of asthma or asthma attack?"
|2001 -||Current Asthma
Lifetime Diagnosis of Asthma
Asthma Attack Prevalence
Based on the questions, ÒHas a doctor or other health professional ever told you that you had asthma?", followed by, ÒDo you still have asthma?", followed by, "During the last 12 months have you had an episode of asthma or asthma attack?"
For further information, please refer to the Asthma FAQs and FAP attached. March 26, 2002