I don't know how she does it, but Helen Branswell of The Canadian Press has done it again: offered a clear, amazingly prompt report on a complex scientific paper. Via Globalnews.ca: H1N1 pandemic death numbers like season flu. Excerpt:
The H1N1 flu pandemic claimed roughly the same number of lives in 2009 as seasonal flu did on average in each of the four years preceding the pandemic, a new study suggests.
But looking at the total number of deaths is a misleading way to analyze the toll of the 2009 outbreak, said the first author of the paper, Prof. Lone Simonsen of the school of public health at George Washington University in Washington, D.C.
That’s because where about 80 per cent of people who die from seasonal flu are 65 and older, between 62 per cent and 85 per cent of the people who succumbed to pandemic H1N1 were younger than 65.
“It’s apples and oranges because these pandemic deaths are much younger than the seasonal (flu) deaths,” said Simonsen, who has extensively studied the death tolls of known flu pandemics.
“One should be dealing with years of life lost or something to try to really understand the texture as much as the cut.”
When one uses years of life lost as a measuring stick against which to assess the pandemic, its severity is in line with the 1968 Hong Kong flu, the pandemic which preceded the 2009 outbreak, she said.
Michael Osterholm, an infectious diseases expert at the University of Minnesota, agreed years of life lost is a better way to gauge the impact of the 2009 pandemic.
“A flu death is not just a flu death,” said Osterholm, who is the director of the university’s Center for Infectious Diseases Research and Policy.
“While we’d like to prevent all flu deaths, a flu death in a person who has a number of co-morbidities (other diseases) at age 78 is very different than that of a young, pregnant woman — otherwise healthy — at age 22.”
Osterholm was not involved in this study, which was published Tuesday in the journal PLoS Medicine, a publication of the U.S. Public Library of Science. The authors were from the U.S., the Netherlands, Britain and from the World Health Organization in Geneva.
Osterholm noted that the mean age of people who died in the H1N1 outbreak was 40, at a time when life expectancy was 79 years.
Roughly a million people are believed to have died in the 1968 pandemic. But in that event, the mean age of people who died was 62, at a time when the average life expectancy was 71 years.
“Number of deaths is a misleading indicator of the severity of influenza,” Osterholm insisted.
“It’s early, premature deaths that we should be in a position of preventing. And this is what this pandemic pointed out — that this was not seasonal flu.”
Another key finding of the study was that some parts of the world were hit far harder than others, with 20 times more deaths in the Americas than in Europe.
CIDRAP also has an excellent Robert Roos story about the Simonsen study.
