The role of tacit knowledge in communication and decision-making during emerging public health incidents.

Strong communication systems for knowledge exchange are required to prevent, respond to and mitigate the effects of emerging public health incidents (EPHIs). The objective of this paper is to examine how "tacit knowledge" - implicit knowledge used to guide everyday practice - is employed in professional relationships and communication processes between public health and acute care settings. A qualitative study design was used to explore the experiences of key informants from public health and acute care settings in Ontario, Canada, to examine how specific dimensions of tacit knowledge are employed in communications about EPHIs. Twenty-six in-depth interviews were conducted from 2014 to 2015. The results describe the way in which participants employ discretion and knowledge of local context, and rely on relationships built on trust and credibility, to facilitate decision-making and communication during EPHIs. Given the uncertainty characterizing most EPHIs, communicators rely a great deal on their informal knowledge and networks which allow them to remain flexible and respond quickly to changing situations. The results reveal that communication about public health guidance during emergencies is a complex and active process that draws from past experiences of the individuals involved, and is shaped by the requirements of local circumstances. The broader implications of these findings for building resilient and responsive health systems are considered. In particular, for rethinking the authority of standardized forms of evidence in public health decision-making, and the importance of knowledge which is grounded in the uniqueness of specific local contexts.