Sales of inhaled *2-agonist bronchodilators may be related to the increase in asthma deaths. The aim of this study is to find whether prescribed drug therapy was associated with the increased risk of death from asthma and life-threatening attacks (LTA). The "case" group comprised those under 35 years of age who expired or experienced LTA from January 1994 through December 1996. For each case, an age and sex matchedcontrol was selected from asthma patients. Hospital records were reviewed to obtain information on the prescribed drug therapy and clinical asthma severity for the cases and controls. Bivariate analysis with conditional logistic regression models for matched data sets were used to estimate theseverity-adjusted odds ratios for each asthma medication. Twenty-four fatal cases and 54 LTA cases were observed. The crude odds ratio of clinical severity (OR=9.33, 95%CI:2.84-30.7) was larger than unity and with statistical significance. After adjusting for clinical severity, the odds ratios computed for all *2-agonists delivered by metered dose inhaler (MDI) increased (OR=2.08, 95%CI:0.78-5.50) from that of crude analysis. Among those subjects under 20 years of age, the clinical severity-adjusted odds ratio for the use of all *2-agonists by MDI (OR=3.67, 95%CI:0.77-17.5) was higher than that of all subjects. The prescription of f32-agonists by MDI increased the risk of asthma death after taking clinical severity into account. Although not statistically significant, our results suggested that l32-agonists administered by a MDI might have increased the risk of asthma death and LTA in Japan because the magnitude of the effect was similar to that reported in other countries. J Epidemiol, 2002 ; 12:223-228 asthma, asthma death, life-threatening attack, f32-agonist, metered dose inhaler
INTRODUCTIONIn the 1960s, asthma mortality was alluded to during an epidemic on the basis of an ecologic study in England and Wales 1,a and in Japan 3), suggesting that sales of inhaled B2-agonist bronchodilators may have been related to excessive asthma deaths during the epidemic. In the 1980s, a relation between inhaled fenoterol and increased risk of death from asthma was reported from New Zealand4-7). However, these findings might be due to a tendency to prescribe the drug more frequently for patients with severe asthma 8).Many investigations were conducted to elucidate uncertainty about the confounding between severity and fenoterol use 4-11) Opinion is still divided: one is that fenoterol was not associated with severe life-threatening attacks (LTA) after controlling severity 8,10);and the other is that the association between fenoterol and asthma death was significant, but after adjustment for markers of asthma severity was made, there was no difference in the magnitude of the association between fenoterol and asthma death 4-7,9,11) In this paper, we report the results of a case-control study on prescribed drug therapy, severity, and the risk of death from asthma and LTA in Japan.
METHODS
Case and Control SelectionIn Januar...