Trends in rates of acute bronchitis episodes presenting in primary care by age group for years 1979-1998 are presented above. Rates of acute bronchitis increased in all age groups, reaching a peak in the early 1990s, declining thereafter. Acute bronchitis is commonest in children aged 0-4 years; followed by the elderly (aged 65 years and over) and is least common in those aged between 5 and 44 years. Between 1979 and 1993 the greatest increase occurred in the elderly.