Google flu trends: Web searches as sensors
Tim Finin, 12:40pm 26 April 2009Google has had a special “flu trends” site up for many months that provides “up-to-date estimates of flu activity in the United States based on aggregated search queries.”
They have found that how many people search for flu-related topics is a leading indicator for reports on how many people actually have flu symptoms. They believe that this metric “may indicate flu activity up to two weeks ahead of traditional flu surveillance systems”. Click on the flash video below to see the relationship between the flu searches and flu symptoms.
So, is Google magic? The explanation for why changes in in the level of flu searches precedes changes in the level of flu symptoms is more mundane.
“So why bother with estimates from aggregated search queries? It turns out that traditional flu surveillance systems take 1-2 weeks to collect and release surveillance data, but Google search queries can be automatically counted very quickly. By making our flu estimates available each day, Google Flu Trends may provide an early-warning system for outbreaks of influenza.”
You can get the details in a recent article in nature:
J. Ginsberg, M. Mohebbi, R. Patel, L. Brammer, M. Smolinski and L. Brilliant, Detecting influenza epidemics using search engine query data, Nature 457, 1012-1014 (19 February 2009).
Of course, such leading indicators may not correlate well if there is a “black swan” flu epidemic or even if there is an unfounded fear of one. Sometimes the crowds are wise, but often not. Remember when we all thought technology stocks real estate was a good thing to invest in?
The Google site also allows you to look at the data by state as well. Click on the image below to try it out.
Ebiquity Blog
April 28th, 2009 at 12:07 pm
[...] Finin, professor of computer science and expert on deep data-mining of the Web and social networks, blogs at UMBC ebiquity about the swine flu outbreak and how Web searches can predict pandemic patterns ahead of an [...]
May 1st, 2009 at 9:33 am
Please stop positioning Google Flutrends as a “Google invention” and regurgitating Google press releases.
NEWSFLASH: The idea to look at search data as early warning systems for flu outbreaks is not a Google invention, but was actually already proposed over 3 years ago (published 2006), by researchers from the Centre for Global eHealth Innovation and U of T.
Eysenbach G. Infodemiology: tracking flu-related searches on the web for syndromic surveillance. AMIA Annu Symp Proc 2006:244-248
http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17238340
Eysenbach G. Infodemiology and Infoveillance: Framework for an Emerging Set of Public Health Informatics Methods to Analyze Search, Communication and Publication Behavior on the Internet
J Med Internet Res 2009;11(1):e11
URL: http://www.jmir.org/2009/1/e11
The Virus Chasers
http://www.cihr-irsc.gc.ca/e/35061.html
CIHR Newsarticle (2007) about the infodemiology / infoveillance work at the Centre for Global eHealth Innovation in Toronto
September 2nd, 2009 at 10:53 am
[...] bit of discussion about this back in April with the first wave of H1N1 (swine flu) concerns (e.g., Google flu trends: Web searches as sensors). The article mentions Google Flu Trends and HealthMap, but I was surprised with some of the new [...]