Online Public Attention during the Early Days of the COVID-19 Pandemic: Infoveillance Study Based on Baidu Index.

Background The COVID-19 pandemic has become a major global public health event, attracting worldwide public attention. As a tool to monitor public awareness, the internet search engine has been widely used in public health emergencies. Objective This study aimed to use online search data (Baidu Index) to monitor the public's attention and verify internet search engines' function in public attention monitoring of public health emergencies. Methods We collected the Baidu Index and the case monitoring data from January 20, 2020, to April 20, 2020. We combined Baidu Index of keywords related to COVID-19 to describe public attention's temporal trend and spatial distribution and conducted the time lag cross-correlation analysis. Results Baidu Index temporal trend indicated that the changes of Baidu Index had a clear correspondence with the development time node of pandemic. Baidu Index spatial distribution showed that in the regions of central and eastern China with denser populations, larger internet user bases, and higher economic development levels, the public was more concerned about COVID-19. Also, Baidu Index was significantly correlated with six case indicators of new confirmed cases, new death cases, new cured discharge cases, cumulative confirmed cases, cumulative death cases, and cumulative cured discharge cases. Moreover, Baidu Index was 0-4 days earlier than new confirmed and new death cases, and about 20 days earlier than new cured and discharged cases, while 3-5 days later than the change of three cumulative cases. Conclusions The national public's demand for epidemic information is urgent regardless of whether it is located in the hardest hit area. The public was more sensitive to the daily new case data that represents the progress of the epidemic, but the public's attention to the epidemic situation in other areas may lag behind. We could set Baidu Index as the sentinel and the database in the online surveillance system for infectious disease and public health emergencies. According to the monitoring data, the government need to prevent and control the possible outbreak in advance and communicate the risks to the public, so as to ensure the physical and psychological health of the public in the epidemic.