Flu mortality formula is potentially misleading, say scientists

Flu mortality formula is potentially misleading, say scientists. Calculating the case fatality ratio is tricky, according to new research - %0A " - Imperial College London News Release Under strict embargo for - 00. British Summer Time - Wednesday 15 July 2009 A standard calculation used in forecasting potential numbers of deaths during the swine flu pandemic risks misleading healthcare planners by being open to both over- and under-estimation of the true figures, say the authors of new research published today in the One in seven cases of bird flu could be prevented by closing schools in event of pandemic, says study - The proportion of people who die due to infection during an influenza outbreak - known as the case fatality ratio - is calculated by dividing the number of deaths by the total number of cases in the same time period. Early data from the current swine flu pandemic suggested that the new influenza A (H1N1) virus causes mild disease, with case fatality ratios of around 0.5%, or 5 deaths per 1000 people infected. However, the researchers from the MRC Centre for Outbreak Analysis & Modelling at Imperial College London, say this ratio may not be accurate. They highlight three reasons for the inaccuracy. Firstly, that the total number of deaths during this pandemic is being underestimated because the cause of death is not correctly attributed to swine flu (e.g.