In recent decades, several epidemiological studies have been published
on acute otitis media
(AOM), indicating that the occurrence of AOM is increasing. However, the
comparison
between the surveys is complicated and biased by several factors, e.g.
variable study
demography and design and dissimilar diagnostic criteria. The present study
was performed
with an identical set-up in 1978–9 and 1994–5 to find out potential
changes in the occurrence
of AOM. All the attacks of AOM among children under 10 years diagnosed
by a physician
during the 12-month periods 1 June, 1978 to 31 May 1979 and 1 June 1994
to 31 May 1995
were registered retrospectively in two Finnish municipalities. The incidence
rate (total number
of AOM attacks per 100 child years) was 19 (95% CI 18–21) in 1978–9
and 32 (95% CI
30–34) in 1994–5. The increase in the occurrence of AOM was
68% (95% CI 53–79%,
P<0·001).