he influenza A (H1N1) pandemic has generated a large volume of cohort data with respect to anti-viral therapy, but to date this has not been systematically reviewed. We performed a meta-analysis of all studies of laboratory-confirmed pH1N1 influenza infection in adults and children which correlated antiviral therapy with hospitalization, ICU admission or death. Early antiviral therapy (<48 hours from symptom onset) was associated with a statistically significant decrease in ICU admission and death. There was no improvement in clinical outcomes when antiviral therapy in general was compared to no antiviral therapy. The literature on therapy for pandemic H1N1 (pH1N1) consists largely of observational studies and is insufficient to draw strong conclusions about the effectiveness of antiviral therapy.