Asthma data from the Swiss Sentinel Surveillance Network, 1989-2005 - from monitoring to research.

Questions Under Study / Principles: The Swiss Sentinel Surveillance Network (SSSN) has been used as a monitoring system for asthma epidemiology. Three aspects of asthma were studied between 1989 and 2005: the seasonal pattern of asthma, practice incidence and time trends for allergic and non-allergic asthma on the basis of the association of asthma with eczema and hay fever. The purpose of this report is to use the results from 17 years of asthma monitoring to show that the SSSN can be used as an instrument of research in practice.

Methods: Basically, monthly and yearly rates of episodes per 1000 consultations were calculated from weekly reports, and standard time series analysis methods were used to explore trends.

Results: The seasonal pattern shows distinct peaks of asthma attacks in June and November. Long-term trends show that consultations for first asthma episodes increased up to 1999 and fell thereafter. Consultations for subsequent asthma episodes have fallen by a third since 1994. Short-term trends indicate a plateau from 1997 to 2000 before a steep decline. The separate analysis of allergic and non-allergic asthma shows that the decrease in asthma consultations is chiefly due to the allergic component of asthma.

Conclusion: These findings are similar to those from other studies for the same time-period and show that the SSSN can generate valid scientific data.