ABSTRACT
Objectives: Investigate how the speech context of news conferences reveals the risk communication strategies for health authorities during COVID-19 and measure the evolution of those risk communication strategies. Methods: We collected news conference transcripts concerning COVID-19 for the first quarter from the official websites of the Centers for Disease Control and Prevention (CDC) and the National Health Commission of the People's Republic of China (NHC) in 2020. Quantitative analyses were conducted on the topics and emotions of transcripts to measure the evolution of risk communication strategy. A total of three types of analysis were carried out in our study: topic, sentiment, and risk communication evolution analyses. Results: The trending topics and the number of these in the two institutions evolved with the infection status. The CDC and NHC maintained primarily neutral sentiment, while the non-neutral sentiment of the CDC swung more dramatically. Furthermore, the changing pattern of risk communication evolution for the CDC and NHC varied, where the latter had a more stable change routine. Conclusion: Our study finds that the strategies could be measured by topic variation, emotional expressions, and confirmed cases. The CDC and NHC tend to adopt different risk communication strategies and have specific change routines facing the pandemic. In addition, our findings contribute to addressing the WHO research agenda for managing risk communication during the COVID-19 pandemic, which helps health authorities formulate and measure risk communication strategies.