A case for communicating uncertainty


We all want clear messaging on preventing the spread of COVID-19, whether it relates to vaccines, face masks, social distancing or any other guidance.

That reflects our mantra within the healthcare communications industry: provide clear, concise and consistent messages that audiences understand.

But science, by its nature, is associated with a level of uncertainty. And although as an industry we are skilled in communicating uncertainty among each other, by including hazard ratios and p-values, we are often hesitant to communicate levels of uncertainty with the public and other stakeholders. Some even argue that ‘the drive to increase transparency regarding the uncertainty of the scientific process specifically does more harm than good’.1

But the novelty of COVID-19 means that our knowledge about the condition, its treatment and prevention is all quickly evolving, and will continue to do so for some time to come. The impact of the disease on human physical and mental health is not yet fully understood. As the situation continues to unfold, government and public health bodies’ guidance around the pandemic will need to change, based on the most recent events and insights. We not only follow very different rules in the UK now than we did in March 2020, but we also follow different rules than are currently prevalent in Sweden, South Korea or New Zealand, among others. This has not gone unnoticed.

It has been pointed out by critics that the public health messaging around guidelines has not been consistent and that not all regulations have had the desired effects. For example, first we were told that face masks wouldn’t make a difference, then that they were preferred, and now they are mandatory in many indoor public spaces across the UK. Other countries leave it up to the public to decide. And some countries, such as Italy, require them everywhere, even in outdoor spaces. Yet how much protection masks provide—to the wearer and to those around them—has continued to evolve, even as the scientific understanding of whether the virus is airborne has evolved. Some critics use the discrepancies as an excuse to disregard guidance and to even encourage others to not follow the latest rules.

The fear felt by science communicators is often that when science is communicated with a message of uncertainty, that this will invite criticism and erode public trust.2 However, research shows that delivering a message with too much certainty can, in fact, cause confusion and undermine public confidence and trust when the messaging later needs to be adapted to reflect emerging new insights or findings.3 The constantly evolving messages, combined with a lack of visible and causal results (it is difficult to prove what hasn’t happened and also why) can undermine the confidence in communications around COVID-19 and science in general. Acknowledging that there are levels of uncertainty that come with science—and that most assumptions are built on a hypothesis—is not only the accurate way to communicate, but can be highly effective in sharing the latest understanding without undermining public trust in science.3,4

Public trust was already an issue with vaccines prior to the pandemic. Even now, during a pandemic that puts vulnerable groups at significantly increased risks, there are challenges with getting communities to receive flu vaccines (for more on this topic, please see: Taking steps to ensure flu vaccinations are a priority in a pandemic).

Now, others – even those who consider themselves ‘pro-vaccine’ – fear the clinical trials for COVID-19 vaccines have been rushed and that there aren’t enough data to trust a vaccine’s efficacy and safety. (For more information on this topic, please see: Understanding people’s fears and concerns relating to COVID-19 vaccines.) There lies a real onus with the pharmaceutical industry and academic research institutions to ensure timely publication of the full interim and final results of their Phase III clinical trials on COVID-19 vaccines. Not only for transparency reasons, but also to provide public health communicators with sufficient information to contextualize their key messages and guidance around vaccines.

COVID-19 has laid bare the need for clear science communications, but it also has shown the importance of balanced science communications, which acknowledge there may be different perspectives that need to be taken into consideration, particularly in scenarios when the scientific community is gaining a better understanding of the situation as it unfolds. Being transparent while also providing clarity and instilling confidence is a challenge for communicators, politicians and media alike, but one that is necessary to keep the public’s trust and fight the raging pandemic together. (For more on considering the challenges different groups will face, please see: We finally have a vaccine, but will this bring about a return to normality?)

Do you want to talk about how to communicate around uncertainty in healthcare or are you in need of strategic communication planning around a complex healthcare topic? We are here to help.


  1. M. Osman, A. J. Heath, R. Löfstedt, The problems of increasing transparency on uncertainty. Public Underst. Sci. 27, 131–138 (2018). Last accessed 8 December 2020: https://journals.sagepub.com/doi/abs/10.1177/0963662517711058
  2. A. M. van der Bles et al. The effects of communicating uncertainty on public trust in facts and numbers. PNAS, 2020, 117 (14); 7672-7683. Last accessed 8 December 2020: https://www.pnas.org/content/117/14/7672
  3. S.E. Kreps & D. L. Kriner. Model uncertainty, political contestation, and public trust in science: Evidence from the COVID-19 pandemic. Science Advances 21 Oct 2020: Vol. 6, no. 43. Last accessed 8 December 2020: https://advances.sciencemag.org/content/6/43/eabd4563
  4. M. J. Steijaert et al. Two-sided science: Communicating scientific uncertainty increases trust in scientists and donation intention by decreasing attribution of communicator bias. Communications: The European Journal of Communication Research 6 June 2020. Last accessed 8 December 2020: https://www.degruyter.com/view/journals/comm/ahead-of-print/article-10.1515-commun-2019-0123/article-10.1515-commun-2019-0123.xml

Get in Touch

We know there are numerous considerations when it comes to the impact of COVID-19 and what this means for your organization. We are here to help.