International trends in asthma mortality rates in the 5- to 34-year age group: a call for closer surveillance.
BACKGROUND
International time trends in asthma mortality have played an important sentinel role in the identification of two epidemics of asthma mortality in some countries in the 1960s and the 1970s and 1980s. Since then, little attention has been paid to the ongoing international time trends.


METHODS
Country-specific data on asthma mortality rates since 1960 in the 5- to 34-year-old age group were collated. To be included in the analysis, countries were required to have data available prior to 1980. A scatter plot smoothing technique was used to model the change in asthma mortality rates with time.


RESULTS
Asthma mortality rates from 20 countries were included in the analysis. An increase in asthma mortality rates was found in the 1960s, with a mean increase of 53% from 0.55 per 100,000 in 1960 and 1961 to a peak of 0.84 in 1966 and 1967. This trend was followed by a progressive decline to a nadir of 0.45 per 100,000 in 1974 and 1975. A gradual increase was then found in asthma mortality rates to a peak of 0.62 per 100,000 in 1985 and 1986, with a mean increase of 38% during this period. Since the late 1980s, there has been a widespread and progressive reduction in mortality rates to a level of 0.23 per 100,000 in 2004 and 2005, with a mean reduction of 63% during this period.


CONCLUSIONS
The widespread increase in asthma mortality in the 1980s and the subsequent, even greater reduction has largely gone unrecognized. We propose that awareness of such trends and their causes is important and that they are investigated contemporaneously.
Medical Research Institute of New Zealand, Wellington, New Zealand.
Meme
M
Wijesinghe
Department of Medicine, University of Otago Wellington, Wellington, New Zealand.
Mark
M
Weatherall
Medical Research Institute of New Zealand, Wellington, New Zealand.
Kyle
K
Perrin
Department of Medicine, University of Otago Wellington, Wellington, New Zealand.
Julian
J
Crane
Medical Research Institute of New Zealand, Wellington, New Zealand. Electronic address: Richard.Beasley@mrinz.ac.nz.
Richard
R
Beasley
D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000401:mortality*; D002648:Child; D002675:Child, Preschool; D006801:Humans