A reappraisal of the United Kingdom epidemic of fatal asthma. Can general mortality data implicate a therapeutic agent?

The 1960s epidemic of asthma deaths that affected young persons in England and Wales, as well as in other countries, was attributed to the effect of newly available pressurized aerosols containing sympathomimetic bronchodilators. The subsequent decision to ban the nonprescription sale of these agents in the United Kingdom represented a unique use of national and international mortality data. The application of such data for decisions about therapeutic agents has implications for the current rise of asthma deaths in New Zealand, for the recent United States regulatory action regarding the nonprescription sale of aerosolized bronchodilators, and for the appraisal of adverse reactions to other pharmaceutical substances. This article is concerned with the quality of the scientific evidence used to implicate bronchodilators in the 1960s epidemic, and also with the strengths and weaknesses of the ecologic studies on which the implication depended. After concluding that the causal link between asthma deaths and bronchodilators was not supported by satisfactory scientific evidence, we present new data and an alternative diagnostic-exchange hypothesis that may, in part, help explain the original association.