Dawood, F., Iuliano, A., Reed, C., et al. (2012). Estimated Global Mortality Associated with the First 12 Months of 2009 Pandemic Influenza A H1N1 Virus Circulation: A Modelling Study. The Lancet Infectious Diseases. 12(9):687-695.
The authors estimated more than 200,000 respiratory deaths with more than 83,000 additional cardiovascular deaths worldwide associated with 2009 influenza A H1N1. This mortality estimate is 15 times higher than the number of reported laboratory-confirmed deaths.