title: Influence of World Thrombosis Day on digital information seeking on venous thrombosis: a Google Trends study.
abstract: Essentials In 2014, World Thrombosis Day (WTD) was initiated to increase global awareness of thrombosis. Google Trends can be used freely to monitor digital information seeking behavior. We used Google Trends data to assess the impact of WTD on internet searches on venous thrombosis. The WTD period was associated with more searches on thrombosis compared to control periods.
  
  
  
  Background World Thrombosis Day (WTD) was launched in 2014 and is to be held every year to increase global awareness of venous thrombosis. Measuring the impact of health awareness days is challenging; however, use of internet-based data seems promising. Methods Google Trends data were used to quantify digital searches for 'venous thrombosis' worldwide and 'trombose' in the Netherlands. The relative search volume (RSV), which is the proportion of the term of interest amongst all Google searches for a specific region and timeframe was used. Mean differences for 4 weeks surrounding WTD (period of interest) and the remaining weeks of the year (control period) were estimated with 95% confidence intervals (95% CI). This was done for 2014, 2015 and 2009-2013 (control years). Results and discussion Mean differences in RSV for worldwide searches were 2.9 (95% CI, -8.2, 14.1) in 2014 and 10.5 (95% CI, 0.4, 20.5) in 2015. These figures were 15.3 (95% CI, 4.7, 25.8) and 15.9 (95% CI, 7.8, 24.1) for the Netherlands, respectively. Relatively, this corresponds to an increase in RSV of 3.9% and 13.9% for 2014 and 2015 worldwide and a 21.9% and 23.3% increase for 2014 and 2015 in the Netherlands. There was one control year with an increase in RSV in the WTD period. Conclusion In 2014 and 2015 WTD was associated with an increase in digital information seeking on venous thrombosis worldwide. This association was more pronounced in 2015 than in 2014.
authors.affiliation: Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands.|Department of Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: L J J
authors.initials: LJ
authors.lastname: Scheres
authors.affiliation: Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: W M
authors.initials: WM
authors.lastname: Lijfering
authors.affiliation: Department of Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Middeldorp
authors.affiliation: Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands.|Department of Internal Medicine, Section of Thrombosis and Haemostasis, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: S C
authors.initials: SC
authors.lastname: Cannegieter
mesh_terms: D022126:Access to Information; D006801:Humans; D057226:Information Seeking Behavior; D020407:Internet; D009426:Netherlands; D020246:Venous Thrombosis / Q000175:diagnosis* / Q000628:therapy*
keywords: Google Trends; World Thrombosis Day; health impact assessment; information seeking behavior; venous thrombosis