Background During the wave 1 of the influenza A ( H 1 N 1)pdm09 virus, Norway appeared to be suffering from high mortality rates. However, by the end of the pandemic, it was widely reported that the number of deaths were much lower than previous years. Objectives The mortality burden from influenza is often assessed by two different approaches: counting influenza‐certified deaths and estimating the mortality burden using models. The purpose of this study is to compare the number of reported deaths with results from two different models for estimating excess mortality during the pandemic in N orway. Additionally, mortality estimates for the pandemic season are compared with non‐pandemic influenza seasons. Methods Numbers on reported influenza A ( N 1h1)pdm09 deaths are gived by the C ause of D eath R egistry at S tatistics N orway and an ad hoc registry at the N orwegian I nstitute of P ublic H ealth. Overall and P nemumonia and I nfluenza certified mortality is modeled using P oission regression, adjusting for levels of reported influenza‐like illness and seasonal and year‐to‐year variation. Results and conclusions Modelling results suggest that the excess mortality in older age groups is considerably lower during the pandemic than non‐pandemic seasons, but there are indications of an excess beyond what was reported during the pandemic. This highlights the benefits of both methods and the importance of explaining where these numbers come from.
【저자키워드】 pandemic, Influenza, modelling, Reporting, excess mortality,