Two epidemics of asthma deaths in people aged five to 34 years have been reported over the last two decades. The first occurred during the mid-1960s in the United Kingdom, Australia, and New Zealand, while the second occurred as an apparently isolated phenomenon in New Zealand in the late 1970s. A full explanation for these epidemics of asthma deaths remains elusive. The cardiotoxic effect of isoprenaline forte aerosols, over-reliance on symptom relief by bronchodilator treatment in severe acute attacks, and secular changes in the prevalence and severity of asthma have been suggested as contributing factors. To determine whether the New Zealand experience during the late 1970s was an isolated phenomenon, or the most obvious example of an international trend, this paper examines recent trends in reported death rates from asthma in 14 countries with suitable statistical data.
Death rates from asthma during the period 1970 to 1984/5 in the five-to-34 years age group were derived from the published national health statistics of Australia, Canada, England and Wales, Finland, France, Japan, Israel (Jews only), the Netherlands, New Zealand, Singapore, Sweden, Switzerland, the United States, and West Germany. Data for 12 other countries in Europe, Asia, and Africa were sought but were either not received, were incomplete, or were in a form unsuitable for this analysis. The 1984 and 1985 data, where given, were obtained from unpublished reports supplied by government statistics departments in each country. Asthma mortality refers to those deaths classified under the rubric 493 covered by the eighth and ninth revisions of the International Classification of Diseases (ICD). To examine the possibility that changes in diagnostic fashion may have caused shifts in classifications of deaths from asthma, deaths from all other respiratory diseases in the five to 34 year age group in New Zealand, England and Wales and the United States were also reviewed. The crude mortality rates are presented without standardization for age as in a previous report standardization made little difference to death rates in the age group under consideration.