Are We Experiencing a Flu Epidemic and Other Problems With Search Terms

Trends in online behavior are fascinating. Bill Tancer, in Click, analyzes why fewer porn sites are accessed on Thanksgiving and other aspects of what people do online. When people are sick, they seek health information online, with the Internet surpassing doctors as a source of health information for the first time, according to Manhattan Research. It is not surprising that many people turn to the Internet to learn about the symptoms of or diagnose a case of influenza.

When all these ill people do their health searches, Google Flu Trends uses their data for early detection of an outbreak, having found “a very close relationship between the frequency of these search queries and the number of people who are experiencing flu-like symptoms each week.” This “fruitful marriage of mob behavior and medicine” has been validated with data from Yahoo as well, according to the New York Times.

They must have found that enough people do Google searches on reasonable terms for Google Flu Trends to detect an outbreak of the flu. While it is heartening to think that the flu and other diseases can be detected in this way (remember SARS?), I am concerned about relying too heavily upon this means of detection because there are many other things to do when you think you have the flu and even if you do a Google search it doesn’t mean you have the flu.

1) What people do when they have flu symptoms:

• Call Mom (did Manhattan Research rank Mom with the Internet and doctors as as a source of health information?)
• Email Mom
• IM a friend
• Tweet many friends (while checking out the CDC’s flu prevention tips)
• Post a question in the countless sites with discussion forums or Q&A
• Look on WebMD, Mayo Clinic, or another health website
• Use a specialized medical search engines
• See a doctor

I assume that all the data resulting from these activities is not tracked by Google Flu Trends. The data that is included is from the use of Google. Which brings us to the second point, that of the dangers of extrapolating too much from search terms.

2) Search terms are not accurate indicators of disease because:

• False-positives can occur. There have undoubtedly been many searches on “flu” to learn more about Google Flu Trends yet this does not mean we are currently experiencing a flu epidemic.
• Only a doctor knows for certain. People with a cold or a fever from another cause may use the same terms Google associates with the flu. In fact, they may think they have the flu.
• People with flu symptoms may search terms or creative misspellings Google isn’t tracking.

Many successful technologies are used in ways other than the originally intended ones and, even if this one doesn’t help the CDC, there is entertainment: “For those of you with the dichotomous penchant for tracking disasters like hurricanes, Google Flu Tracker will be great fun.” For humor, check out the Ads by Google accompanying some of the posts about this news; I saw orange juice advertised to “fight those nasty cold and flu bugs” as well as information on “why flu shots may or may not be advised for you.” Search terms are useful in oh so many ways.