Objective: To evaluate which factors present at the onset of acute sinusitis predict the duration of illness among adult patients treated with antibiotics.
Design: Cohort study with a 30-day follow-up.
Setting: Norwegian general practice.
Subjects: Eighty-six adult patients with a clinical diagnosis of acute sinusitis confirmed by Computed Tomography.
Methods: Signs, symptoms and other variables present at the onset of treatment were dichotomized and analysed bivariately with duration of the sinusitis episode, using the log-rank test. Age, gender, and factors with p-values under 0.15 were modelled in a Cox regression analysis to assess independent predictors for illness duration.
Main outcome measure: Duration of illness.
Results: Illness duration was significantly and positively associated with increasing age and with a higher clinical severity score at the onset of treatment. No other factors were independent predictors of illness duration.
Conclusion: The age of the patient and the clinical severity of the sinusitis at the onset of treatment were independent predictors of illness duration in adult patients treated with antibiotics.