Objective: The objective of this study was to evaluate the diagnosis and treatment of acute sinusitis at three health care centers in northern and eastern Iceland.

Material and methods: Information on all those diagnosed with acute sinusitis (ICD 10 J01.0, J01.9) in the year 2004 at the communal health care centers in Akureyri, Husavik and Egilsstadir was obtained retrospectively from computerized clinical records. Key factors used for diagnosis and treatment were recorded. In order to obtain an equal distribution in population size  only about one-third of the diagnoses made in Akureyri were included in the search (the first ten days of every month). 

Results: The search yielded a total of 468 individuals.  The average incidence of acute sinusitis was found to be 3.4 per 100 inhabitants per year. Adherence to clinical guidelines (albeit from other countries) regarding diagnosis of bacterial sinusitis was nearly nonexistent. There were considerable differences found between health care centers as to whether x-rays were used for diagnostic purposes.  Blood tests were hardly used at all. The disease was diagnosed over the telephone in 28% of the cases (Husavik 38%, Akureyri 32%, Egilsstadir 10%). Over 90% of all individuals diagnosed with acute sinusitis received antibiotics, regardless of symptom duration. The antibiotics most often prescribed were Doxycyclin and Amoxicillin.

Conclusions: The incidence of acute sinusitis in these three communities  seems to be similar to other western countries. Acute bacterial sinusitis seems to be overdiagnosed and the use of antibiotics is in no context with clinical guidelines. Our results support the hypothesis that physicians tend to regard acute sinusitis as a bacterial disease, and treat it accordingly.