Trends in asthma mortality in New Zealand, 1908-1986.

Trends in mortality from asthma in non-Maori New Zealanders aged 5 to 34 years were examined for the period 1908-1986. Two previously documented epidemics of death from asthma occurred in the 1960s and the late 1970s. These epidemics are most likely to have been due to changes in the management of asthma: the introduction of isoprenaline forte by metered dose inhaler in the 1960s and inhaled fenoterol in the 1970s. A previously unreported rise in mortality, which was more gradual in onset and less severe, occurred in the 1940s and 1950s; a similar pattern occurred in England and Wales during the same period. It is unlikely that this increase in mortality was solely due to changes in diagnostic fashion or disease coding. Possible explanations include changes in the management or prevalence of asthma, or in environmental factors. It is notable that mortality was below 0.5 per 100,000 person-years prior to 1940, but has subsequently increased considerably. Thus, while modern methods for treating asthma have improved the quality of life of many asthmatics, mortality has increased during the period of their introduction and use.