Changes in asthma prevalence and impact on health and function in Seattle middle-school children: 1995 vs 2003.

BACKGROUND: The prevalence of asthma has increased during the past several decades but may have stabilized during the last 5 years. It is not known whether the functional and health impact of asthma has decreased during the past decade.
OBJECTIVE: To evaluate changes during a recent 8-year period in the prevalence and health and functional impact of current asthma symptoms in young teenagers.
METHODS: In 1995 and 2003, 2,330 and 2,397 middle-school students from Seattle, WA, respectively (median age, 13 years), completed written surveys and answered questions pertaining to 4 wheezing or asthma video scenarios. Children were categorized as having physician-diagnosed current asthma (wheeze in the past year and a physician diagnosis of asthma), undiagnosed current asthma symptoms (wheeze in the past year without a physician diagnosis), or no asthma. Outcome measures were the prevalence of asthma and undiagnosed asthma symptoms and the differences between years in respiratory-associated functional impairment (exercise limitation, missed school, disrupted sleep) and health impact (physician visits, wheeze-limited speech).
RESULTS: The prevalence of physician-diagnosed current asthma increased from 1995 to 2003 (3.0% to 6.2%), whereas that for undiagnosed current asthma symptoms decreased (12.0% to 6.2%). The degree of functional and health impairment was similar between the 2 study periods for each subgroup and was highest in the children with physician-diagnosed current asthma.
CONCLUSIONS: The prevalence of current asthma symptoms in middle-school children from Seattle decreased slightly between 1995 and 2003, whereas the diagnosis of asthma increased. However, the health and functional impact of asthma did not diminish. Asthma is being diagnosed more often, but many children with asthma are still not achieving good asthma control.