Prevalence of asthma and asthma action plans in South Australia: population surveys from 1990 to 2001.

OBJECTIVES: To assess trends in the prevalence of self-reported doctor-diagnosed asthma, associated asthma related morbidity, and the uptake of written asthma action plans in South Australia, 1990-2001.

DESIGN, SETTING AND PARTICIPANTS: Surveys by telephone interview of the South Australian population between 1990 and 2001, and interview of participants in their own homes by trained health interviewers.

MAIN OUTCOME MEASURES: Asthma prevalence, percentage of patients with written action plans, and asthma associated morbidity.

RESULTS: The reported prevalence of doctor-diagnosed asthma has increased from 8% (95% CI, 6.4%-9.6%) in 1990 to 12.8% (95% CI, 11.4%-14.2%) in 2001. Morbidity, as measured by wakening at night (daily or weekly) and days lost from normal activities because of asthma, has remained constant over the decade. The percentage of patients with written asthma action plans increased to a peak of 42.3% (95% CI, 40.3%-44.3%) in 1995, but then declined to 22.2% (95% CI, 20.7%-23.7%) in 2001.

CONCLUSIONS: The prevalence of asthma has increased while morbidity has remained constant, indicating that the burden of asthma has increased. The associated decline in the percentage of patients with asthma action plans in recent years is cause for concern.