Epidemiologic Studies of Asthma Epidemics in Barcelona

¹ The Department d'Epidemiologia i Salut Pública, IMIM, Barcelona, Spain.

The respiratory emergency monitoring system developed in Barcelona to study asthma epidemics has proved to be a useful epidemiologic tool. It has mainly contributed to (1) case finding of asthma outbreaks; (2) the development of a useful definition of asthma epidemic days; (3) the setting up of a time—ecological design; (4) the provision of a framework for subject selection in a case—control study; and (5) the design of an intervention study for the evaluation of control measures in the harbor. However, these contributions, although clearly positive, should be considered in light of the conceptual and methodologic limitations enumerated earlier.

Finally, research into Barcelona asthma epidemics, employing principles of epidemiologic surveillance, has led to the identification of a specific etiologic hypothesis that has been tested using analytic designs. The validity of this hypothesis has been demonstrated and has enabled the causative point source to be removed. After this intervention, no other asthma outbreaks were observed.