Abstract
Objective: Otitis media (OM) is a common disease in childhood, but much
less prevalent in adults, where it, however, tends to have a less benign
course. The incidence of OM in children has decreased in recent years,
which might be partly explained by the introduction of watchful waiting
strategies, and by the introduction of conjugate pneumococcal
vaccination (PCV) in children. Adult OM has been sparsely studied, and
it is not known whether a herd immunity effect has been achieved after
the introduction of PCV. Watchful waiting is usually not considered in
adult OM patients. The purpose of this study was to use a national
database to investigate the incidence of adult OM in Sweden during the
last 20 years. Design: The yearly number of patients aged 20 and over,
admitted to hospital with OM was obtained through a national database
from 2000 to 2019. The corresponding numbers for outpatients were
obtained between 2005 and 2019. Main outcome measures: incidence of
acute otitis media in adults in in- and outpatient care. Results:
Incidence rates decreased steadily during the study period. Comparing
data on hospitalised patients from 2016-2019 to 2005-2008 (PCV was
introduced in 2009), the incidence rate ratio was 0.49 (95% CI
0.45-0.53); p<0.0001. The corresponding figures for
outpatients were 0.62 (95% CI 0.61-0.63); p<0.0001. The
decrease in hospital admissions was most pronounced among younger
patients, whereas the opposite was true for outpatient visits.
Conclusions: There has been a continuous decrease in incidence of adult
patients admitted to hospital with OM in Sweden during the last twenty
years. Outpatient visits for OM have declined since 2009.