Descriptive comparison of all virological notifications (VN), those with an any-cause ED presentation, hospital admission or death registration, and of coded influenza and certified influenza deaths in the databases, New South Wales, Australia, 2005–2008.

Notes:
na  =  not applicable.
1.Two hospital admission records with coded influenza had missing age and sex.
2.Coded influenza admissions were based on all 51 available admission diagnosis fields.
3.Two registered deaths had no cause recorded.
4.Coded influenza in the primary ED diagnosis in the ED database, or in any available admission diagnosis in the admission database, or influenza certified as a cause of death in the death database.