How informative are web searches for risk communication during COVID-19 in Germany?

Background: Risk communication during pandemics is an element of paramount importance. Understanding the level of public concern implicates expensive and time-consuming surveys. We hypothesize that the relative search volume from Google Trends could be used as an indicator of public concern towards prevention measures as well as of the adequacy of the official messages spread. Methods: : The search terms ‘ RKI ’, ‘ corona ’ and ‘ protective mask’ in German language were shortlisted. Cross-correlations between these terms and the reported cases from February 15 th to April 27 th were conducted for each German federal state. The findings were contrasted against a timeline of official communications concerning COVID-19. Results: : The highest correlations of the term ‘ RKI’ (Robert Koch Institute, national public health authority in Germany) with reported COVID-19 cases were found between lags of -2 and -12 days, meaning web searches were already performed two to twelve days before case numbers increased. A similar pattern was seen for the term ‘ corona ’. Cross-correlations indicated that most searches on ‘ protective mask ’ were performed six to twelve days after the increase of cases. Conclusions: : The results for the term ‘ protective mask ’ indicate some degree of confusion in the population, which is supported by the contradictory recommendations on the wearing of face masks over time. In addition, the relative search volumes could be a useful tool to provide timely information on location-based risk communication strategies.