Incidence of episodes of acute asthma and acute bronchitis in general practice 1976-87.

The incidence of episodes of acute asthma and acute bronchitis was analysed for an 11-year period and studied in relation to epidemiological data on viral illness and virus isolation data. Between 1976 and 1987, the weekly returns service estimates of the incidence of acute asthmatic episodes in England and Wales increased from 10.2 to 27.1 per 100,000 patients per week (all ages). The increase was most marked in children up to the age of 14 years. Acute bronchitis attack rates (all ages) increased from 78.7 to 111.9 per 100,000 patients over the same period. Because of this rise in rates of acute bronchitis, it is unlikely that labelling shifts contributed to the increase in reported episodes of asthma. These data support the belief that the rise in the prevalence of asthma is real, and also that in the United Kingdom this rise may even be underestimated by partial concealment in the rates of acute bronchitis. In 1987, if 10% of attacks of acute bronchitis were attacks of asthma, this would represent a 41% underestimation of asthma attack rates. Rates for other respiratory illnesses showed a fall over the same period, apart from the common cold which showed an increase. The winter increase in acute bronchitis coincided with viruses with strong seasonal patterns (respiratory syncytial virus, parainfluenza viruses 1 and 2 and influenza A and B), but there was no evidence that these viruses were related to the overall increase in acute asthma attacks over this 11 year period.(ABSTRACT TRUNCATED AT 250 WORDS)