Kidney stone seasonality reflected in online searches

Seasonal variations in kidney stone incidence appear to be reflected in Google search engine queries, according to researchers at the University of California, San Francisco.

First author Benjamin Breyer, MD, and colleagues used an online tool called Google Insights for Search to see whether the varying popularity of search terms would reflect seasonal and geographic differences in kidney stone prevalence.

The researchers compared monthly Google search volume for the nation, for individual states, and for two metropolitan areas with high rates of Internet use-New York and Seattle-with kidney stone diagnosis data from the National Inpatient Sample.

Nationwide, trends over the course of a year in the relative popularity of searches for "kidney stones" roughly mirrored changes in actual hospital admissions for kidney stones.

Google Insight for Search output for the search term "kidney stones" and hospital admissions for kidney stones recorded in the Nationwide Inpatient Sample trace a seasonal trend.

Similarly, Google searches for “kidney stones” ranked higher as a percentage of total searches in regions of the country where kidney stones actually were more common in the hospital discharge records.

In addition, the researchers found that variations in search volume in Seattle and New York over several years reflected seasonal temperature changes.

Analysis of search data should allow researchers to explore new ideas about possible links between illnesses and changes in our surroundings, Dr. Breyer said.

"I think it represents a really exciting way to study the pathophysiology of disease," he said.

Study results were published in Urology (2011; 78:267-71).