@article{ref1,
title="Search trends preceding increases in suicide: a cross-correlation study of monthly Google search volume and suicide rate using transfer function models",
journal="Journal of affective disorders",
year="2019",
author="Lee, Joo-Young",
volume="262",
number="",
pages="155-164",
abstract="BACKGROUND: Various associations between monthly Google search volumes (MGSVs) and monthly suicide rates (MSRs) have been reported. However, these studies often analyzed a limited number of search terms using suboptimal statistical methods. While controlling for spurious associations, this study examined a wide array of suicide-related search terms to elucidate if their MGSVs correlated with future MSRs. <br><br>METHODS: MGSVs of 111 candidate suicide-related terms were calculated by averaging 10 time-series data per term obtained from Google Trends. Box-Jenkins transfer function modeling was applied to time-series data of MGSV and MSR among the total, male, and female populations of the United States between 2004 and 2017. Cross-correlation coefficients between MGSVs and MSRs were calculated at lags -3, -2, and -1. Sensitivity analysis identified cross-correlations whose direction and significance (p<0.05) persisted in two other time spans: 126 and 84 months. <br><br>RESULTS: Eighty-nine terms were analyzed. MGSVs of 31 terms significantly correlated with MSRs in the total, male, or female population. In the sensitivity analysis, three terms stably exhibited significant positive correlation: &quot;generalized anxiety disorder&quot; (total; lag -3), &quot;anxiety disorder&quot; (total and male; lag -3), and &quot;laid off&quot; (total, male, and female; lag -2). The term sleep problem (total and female; lag -1) consistently showed significant negative correlations. LIMITATIONS: Sex- or age-specific search-volume data, lags of less than a month, and potential confounding factors of MGSV and MSR were not explored. <br><br>CONCLUSIONS: trends in MGSV of four terms tend to precede changes in MSR. These terms may enable more accurate forecasting of future suicides.<br><br>Copyright © 2019 Elsevier B.V. All rights reserved.<p /> <p>Language: en</p>",
language="en",
issn="0165-0327",
doi="10.1016/j.jad.2019.11.014",
url="http://dx.doi.org/10.1016/j.jad.2019.11.014"
}