Tuesday, June 27, 2006

Lies, Damned Lies, and Statistics


While Avian Flu News is scarce right now, we are being deluged with `studies’ purporting to warn us of the ramifications of a worst case pandemic. The trouble is, none of these studies appear to use real life numbers, and as troubling as their conclusions appear to be, none come close to a `worst case’ scenario. Reporters, who apparently are math challenged, repeat these numbers in other articles, and soon these `guesses’ become `facts’.


Last year, the number of deaths from a pandemic was stated to be, at a minimum, two to seven million people worldwide. Since then, this estimated death toll has been repeated by governmental agencies, politicians, reporters, and health officials, but often without the important preamble of `at a minimum’. The result has been that many people believe that 7 million deaths from a pandemic is the upper limit.


Folks, 7 million dead from a pandemic is not a worst-case scenario. It’s a best-case scenario.


In 1918, the number of people who died from the Spanish flu is estimated to have been between 50 million and 100 million. And this was at a time when the worlds’ population was 1/3rd of what it is today. A pandemic with the same lethality today would claim between 150 and 300 million lives.


Yet, we still see the 2 to 7 million potential deaths from a pandemic quoted in newspaper articles. Worse, some governmental agencies are using this number to plan around, and if they are planning for the best case, and it doesn’t happen, we will be totally screwed.


Yesterday, a report came out of Australia that, while more realistic than some others I’ve seen, still falls short. It describes the economic fallout, and death toll from a `medium’ pandemic that could claim 80 million lives worldwide.

http://news.antara.co.id/en/seenws/?id=15241


While more realistic than the 2 to 7 million dead, and hedged with the `medium pandemic’ disclaimer, is this really a medium pandemic? More to the point, should we be preparing for a `medium pandemic’?


Some tidbits from the ABARE (Australian Bureau of Agricultural and Resource Economics) report . . .


It estimated that the outbreak would kill 0.2 percent of the population in developed countries and 1.39 percent in developing countries.

Gross domestic product in China would fall 8.7 percent, compared with 6.7 percent in South Korea, 6.1 percent in Japan, 7.1 percent in the Association of Southeast Asian Nations (ASEAN) and 6.8 percent in Australia.

ABARE estimated that GDP in the United States would drop 3.5 percent, in the European Union by 3.7 percent and Canada by 3.0 percent.


In 1918, in the United States, the death toll was nearly 700,000 people. Using the .2% number cited in this report, the death toll would only be 600,000 people in the U.S., even though our population has tripled since then. The assumption, I guess, is that 1918 was the absolute worst-case scenario.


But the H5N1 virus currently claims more than 50% of its victims. And most of those have had the luxury of hospitalization and aggressive use of Tamiflu and ventilators. During a full scale pandemic, most people will have to ride out the illness at home, and without medical heroics. The true CFR (Case Fatality Rate) of H5N1 once it goes pandemic (still an `if’, btw), is unknown.


The hope is, that the virus, if it mutates, will trade lethality for transmissibility. But that is nothing more than a hope. It would have to lose more than 99% of its lethality to get us down to the numbers cited in this report.


Our own government, always willing to water down the numbers to reduce the fear factor, is figuring on 1.9 million deaths in the U.S., or triple the number of this report. For that to happen, H5N1 would only have to lose about 98% of its lethality.


The idea that H5N1 could develop into a pandemic strain and retain its current CFR is unthinkable in many circles. A 30% infection rate, with a 50% fatality rate. That would mean 50 million dead in the U.S. alone. Worldwide, it could mean 1 billion dead. Yet, unthinkable or not, that is the real `worst-case’ scenario. Or at least damn close to it.


One could argue that, beyond a certain number, the impact of a pandemic would be so severe that it wouldn’t matter anymore if the death toll were 300 million, 600 million, or a billion. That it is impossible to prepare for such a calamity, and therefore not worth speculating upon.


Perhaps that’s true.


But if a CAT 5 Hurricane were lurking off the Florida coast, one would be hard pressed to justify telling people to prepare for a tropical storm, based on the faint hope that the 200 mph winds might diminish to 60 MPH before it reached the coastline.