Time-series analyses of firearm-related Google searches and U.S. suicide rates 2004-2016.

OBJECTIVE: The U.S. suicide rate has increased 35% since 1999. The role of the Internet has not been thoroughly investigated despite Internet use more than doubling from 1999 to present. The majority of U.S. suicide deaths are by firearm; however, there is no examination of the association between trends in firearm Internet searches and overall and firearm monthly suicide rates. We hypothesized that search strings related to firearm suicide would be significantly associated with monthly suicide rates (both all methods and firearm). METHODS: Google Trends provides data on request frequencies of searches. Twenty-four search strings were examined representing possible searches by individuals considering firearm suicide and compared to U.S. suicide rates with time-series modeling. RESULTS: In the time series with higher search volumes, consistent associations were found of negative cross-correlation at lag +1. CONCLUSIONS: Several searches appeared at least sensitive enough to consistently show associations with overall and firearm suicide rates in the following month. This novel finding should be followed up as the potential exists to predict suicide trends.

Low validity of Google Trends for behavioral forecasting of national suicide rates.

Recent research suggests that search volumes of the most popular search engine worldwide, Google, provided via Google Trends, could be associated with national suicide rates in the USA, UK, and some Asian countries. However, search volumes have mostly been studied in an ad hoc fashion, without controls for spurious associations. This study evaluated the validity and utility of Google Trends search volumes for behavioral forecasting of suicide rates in the USA, Germany, Austria, and Switzerland. Suicide-related search terms were systematically collected and respective Google Trends search volumes evaluated for availability. Time spans covered 2004 to 2010 (USA, Switzerland) and 2004 to 2012 (Germany, Austria). Temporal associations of search volumes and suicide rates were investigated with time-series analyses that rigorously controlled for spurious associations. The number and reliability of analyzable search volume data increased with country size. Search volumes showed various temporal associations with suicide rates. However, associations differed both across and within countries and mostly followed no discernable patterns. The total number of significant associations roughly matched the number of expected Type I errors. These results suggest that the validity of Google Trends search volumes for behavioral forecasting of national suicide rates is low. The utility and validity of search volumes for the forecasting of suicide rates depend on two key assumptions ("the population that conducts searches consists mostly of individuals with suicidal ideation", "suicide-related search behavior is strongly linked with suicidal behavior"). We discuss strands of evidence that these two assumptions are likely not met. Implications for future research with Google Trends in the context of suicide research are also discussed.