Will Google’s Flu Trends Be Better This Year?
Feeling feverish and achy? How about a sore throat or cough? Any chills?
Unfortunately, it’s that time of year when you may feel like you’re coming down with the flu. If so, what do you do first? Call the doctor? There’s a good chance you’re one of millions who plug “flu symptoms” into your web browser.
It’s not really a surprise that Google has determined that certain search terms are good indicators of flu activity. In 2008, the company launched Google Flu Trends to help estimate the start, peak, and duration of each flu season with aggregated Google search keyword data.
Currently tracking a number of countries worldwide, Google Flu Trends is updated daily. The value-add is that the Google data is typically published in advance of official public health surveillance data, such as from public health agencies like the Centers for Disease Control (CDC).
However, Google’s projections for the 2012-2013 season didn’t work as well as in previous years. Last year, Google came under fire for overestimating the severity of the flu in the United States, compared to the reality of actual healthcare visits for influenza-like illnesses actually reported by the CDC.
The Atlantic Wire was one of many media outlets who lambasted Google Flu Trends for overestimating the 2012-2013 flu outbreak: “Scientific hindsight shows that Google Flu Trends far overstated this year's flu season, raising questions about the accuracy of using a search engine, which Google and the media hyped as an efficient public health tool, to accurately monitor the flu.”
What happened? Apparently media attention (and possibly commercials) skewed Google's search engine traffic and incited flu-sufferers, as well as healthy people, to Google flu terms.
Google Software Engineer Christian Stefansen wrote in a Google blog recently that upon further investigation, “We found that heightened media coverage on the severity of the flu season resulted in an extended period in which users were searching for terms we’ve identified as correlated with flu levels. In early 2013, we saw more flu-related searches in the US than ever before.”
Apparently Google’s algorithm “was susceptible to bias in situations where searches for flu-related terms on Google.com were uncharactistically high within a short period of time. We hypothesized that concerned people were reacting to heightened media coverage, which in turn created unexpected spikes in the query volume.”
Google has re-evaluated and revised its tracking model for the 2013-2014 season and hopefully will more accurately track the flu. If you’re interested in further details, Google presented a paper on its disease tracking and modeling at a conference by the International Society for Neglected Tropical Diseases.
Will Google Flu Trends be more accurate this year? The US flu activity for Georgia currently is reported as “low” on the website. However, our four-year-old had the flu at the end of October and ended up in the emergency room in the middle of the night with a 104 degree fever—and he had already had a flu shot. So “low”—really? And yes, we did Google “flu symptoms” before calling the pediatrician.