We ring in the New Year with hopes of being healthy, wealthy, and wise. A new study from epidemiological researchers and long-time colleagues John W. Ayers of San Diego State University and Benjamin Althouse of the Santa Fe Institute and their colleagues suggests that health and wealth may be more strongly connected than previously thought.

The group examined Americans' Google search patterns and discovered that during the recent Great Recession, people searched considerably more frequently for information about health ailments. The kinds of problems indicated by the queries weren't life threatening, but they could keep someone in the bed a few days, like ulcers, headaches, and back pain.

In total, the team found there were more than 200 million excess queries of this kind during the Great Recession than expected.

"While it's impossible to uncover the motives for increased searches, they likely indicate a person being ill, and ill enough to seek out online information or remedies," Ayers said. The same group previously published a report* showing that queries for anxiety and depression also increased substantially during the Great Recession.

Revealing searches

In the new study*, published in the American Journal of Preventive Medicine, the team began with five root words indicative of the most common health problems: "chest", "headache", "heart", "pain", and "stomach." Controlling for search terms that might return false positives (such as "tool chest"), the researchers measured how frequently people in the United States searched for queries involving those root terms during the Great Recession, here defined as December 2008 through 2011, and came up with a list of 343 symptom queries.

Next, the team calculated what the search volume of those symptoms' queries would have been if there had been no Great Recession - what statisticians call synthetic controls) - correcting for such variables as the growing availability of the Internet and increased usage.

Comparing those values to people's actual search behavior revealed that certain symptoms were searched for with far more frequency during the recession. Searches for "stomach ulcer symptoms" were 228 percent higher than would be expected and "headache symptoms" were 193 percent higher, representing about 1.48 and 1.52 million excess searches.

Aggregating the symptoms into themes, the researchers found that several broad categories of health concerns stuck out: Queries about headaches were 41 percent higher than expected; for hernias, 37 percent; for chest pain, 35 percent; and for heart arrhythmias, 32 percent. Back pain, gastric pain, joint pain and toothache also popped up with greater-than-expected frequency among the search terms.

"The Great Recession undoubtedly got inside the body via the mind," Ayers said. "Job loss or losing a home touched nearly everyone, directly or indirectly. But those who got away unscathed were probably not immune to the Great Recession's health implications, with many thinking 'I could be next'."

Superior surveillance

Althouse, the study's lead author, said that by monitoring health-related search terms, public health officials could recognize burgeoning epidemics and direct resources to help people reduce their stress or take other precautionary measures. This technique is quicker, cheaper, and more efficient than traditional survey based methodologies, he added.

"In fact, many current approaches to public health surveillance are both slow and expensive," Althouse said. "Internet search queries may be a significantly more precise metric, suggesting precisely when and how the population's health could be changing."

"By looking for these more-frequent-than-expected search terms and matching them up to world events, public health officials can conduct population health surveillance on a truly unprecedented scale," added Mark Dredze, a professor of computer science at Johns Hopkins University and one of the study's coauthors.

The team pointed out that their approach could be used to immediately improve public health. For example, search engines like Google could interpret these searches and suggest links to evidence-based, Internet-based treatment options in coordination with health agencies.

"The web is a stigma-reducing and cost-reducing venue to reach patients who search for, but do not otherwise receive, treatment because they cannot afford medications or copayments," said Jon-Patrick Allem, another of the study's coauthor and a doctoral candidate at the University of Southern California Keck School of Medicine.

Matthew Childers, study coauthor and professor of political science at the University of Georgia, added that their findings carry political implications, as well.

"If you just recently had your unemployment benefits slashed, in addition to becoming poorer, you just might end up sicker too," Childers said. "Of the more than $800 billion allocated by the stimulus package, only $9 billion was spent on health promotion, and our study shows how health can have greater salience in economic debates going forward."