Abstract
Evidence, communication, critical thinking and participation are the cornerstones of informed decisions. In this article we discuss each of these in relation to decisions about public health and social measures (PHSM) during the coronavirus disease 2019 (COVID-19) pandemic and implications for future research. Reliable research evidence of the effects of interventions is particularly important for decisions about what to do because it provides the best basis for estimating the wanted and unwanted effects of doing something. There was little reliable research of the effects of PHSM during the pandemic. For research evidence to be useful to decision-makers, it must be effectively communicated, including how sure we can be about effects or other research findings. Research evidence is essential for making informed decisions, but it is not sufficient. Decision-makers and those affected by the decision must be able to think critically about what to believe and what to do. Many people lack competences and dispositions for thinking critically about PHSM or other interventions. Judgements about PHSM require democratic input, not just expert input. However, there was little public participation in deliberative or decision-making processes about PHSM during the pandemic. There are important uncertainties about the effects of PHSM, how to effectively communicate decisions and evidence about PHSM, how to foster critical thinking about PHSM and how to effectively engage the public in deliberative and decision-making processes about PHSM. Pandemic research and preparedness planning should address those uncertainties.