Transparent communication of evidence does not undermine public trust in evidence.

Does clear and transparent communication of risks, benefits, and uncertainties increase or undermine public trust in scientific information that people use to guide their decision-making? We examined the impact of reframing messages written in traditional persuasive style to align instead with recent "evidence communication" principles, aiming to inform decision-making: communicating a balance of risks and benefits, disclosing uncertainties and evidence quality, and prebunking misperceptions. In two pre-registered experiments, UK participants read either a persuasive message or a balanced and informative message adhering to evidence communication recommendations about COVID-19 vaccines (Study 1) or nuclear power plants (Study 2). We find that balanced messages are either perceived as trustworthy as persuasive messages (Study 1), or more so (Study 2). However, we note a moderating role of prior beliefs such that balanced messages were consistently perceived as more trustworthy among those with negative or neutral prior beliefs about the message content. We furthermore note that participants who had read the persuasive message on nuclear power plants voiced significantly stronger support for nuclear power than those who had read the balanced message, despite rating the information as less trustworthy. There was no difference in vaccination intentions between groups reading the different vaccine messages.

Impact of residual risk messaging to reduce false reassurance following test-negative results from asymptomatic coronavirus (SARS-CoV-2) testing: an online experimental study of a hypothetical test.

OBJECTIVES: Individuals who receive a negative lateral flow coronavirus test result may misunderstand it as meaning 'no risk of infectiousness', giving false reassurance. This experiment tested the impact of adding information to negative test result messages about residual risk and the need to continue protective behaviours. DESIGN: 4 (residual risk) × 2 (post-test result behaviours) between-subjects design. SETTING: Online. PARTICIPANTS: 1200 adults from a representative UK sample recruited via Prolific (12-15 March 2021). INTERVENTIONS: Participants were randomly allocated to one of eight messages. Residual risk messages were: (1) 'Your coronavirus test result is negative' (control); (2) message 1 plus 'It's likely you were not infectious when the test was done' (current NHS Test & Trace (T&T); (3) message 2 plus 'But there is still a chance you may be infectious' (elaborated NHS T&T); and (4) message 3 plus infographic depicting residual risk (elaborated NHS T&T+infographic). Each message contained either no additional information or information about the need to continue following guidelines and protective behaviours. OUTCOME MEASURES: (1) Proportion understanding residual risk of infectiousness and (2) likelihood of engaging in protective behaviours (scales 1-7). RESULTS: The control message decreased understanding relative to the current NHS T&T message: 54% versus 71% (Adjusted Odds Ratio (AOR)=0.56 95% CI 0.34 to 0.95, p=0.030). Understanding increased with the elaborated NHS T&T (89%; AOR=3.25 95% CI 1.64 to 6.42, p=0.001) and elaborated NHS T&T+infographic (91%; AOR=5.16 95% CI 2.47 to 10.82, p<0.001) compared with current NHS T&T message. Likelihood of engaging in protective behaviours was unaffected by information (AOR=1.11 95% CI 0.69 to 1.80, χ2(1)=0.18, p=0.669), being high (M=6.4, SD=0.9) across the sample. CONCLUSIONS: A considerable proportion of participants misunderstood the residual risk following a negative test result. The addition of a single sentence ('But there is still a chance you may be infectious') to current NHS T&T wording increased understanding of residual risk. TRIAL REGISTRATION NUMBER: OSF: https://osf.io/byfz3/.

Behavioural responses to Covid-19 health certification: a rapid review.

BACKGROUND: Covid-status certification - certificates for those who test negative for the SARS-CoV-2 virus, test positive for antibodies, or who have been vaccinated against SARS-CoV-2 - has been proposed to enable safer access to a range of activities. Realising these benefits will depend in part upon the behavioural and social impacts of certification. The aim of this rapid review was to describe public attitudes towards certification, and its possible impact on uptake of testing and vaccination, protective behaviours, and crime. METHOD: A search was undertaken in peer-reviewed databases, pre-print databases, and the grey literature, from 2000 to December 2020. Studies were included if they measured attitudes towards or behavioural consequences of health certificates based on one of three indices of Covid-19 status: test-negative result for current infectiousness, test-positive for antibodies conferring natural immunity, or vaccination(s) conferring immunity. RESULTS: Thirty-three papers met the inclusion criteria, only three of which were rated as low risk of bias. Public attitudes were generally favourable towards the use of immunity certificates for international travel, but unfavourable towards their use for access to work and other activities. A significant minority was strongly opposed to the use of certificates of immunity for any purpose. The limited evidence suggested that intention to get vaccinated varied with the activity enabled by certification or vaccination (e.g., international travel). Where vaccination is seen as compulsory this could lead to unwillingness to accept a subsequent vaccination. There was some evidence that restricting access to settings and activities to those with antibody test certificates may lead to deliberate exposure to infection in a minority. Behaviours that reduce transmission may decrease upon health certificates based on any of the three indices of Covid-19 status, including physical distancing and handwashing. CONCLUSIONS: The limited evidence suggests that health certification in relation to COVID-19 - outside of the context of international travel - has the potential for harm as well as benefit. Realising the benefits while minimising the harms will require real-time evaluations allowing modifications to maximise the potential contribution of certification to enable safer access to a range of activities.

Re-opening live events and large venues after Covid-19 'lockdown': Behavioural risks and their mitigations.

This article reviews the behavioural risks and possible mitigations for re-opening large venues for sports and music events when Covid-19 infection rates and hospitalizations begin to decline. We describe the key variables that we suggest will affect public behaviour relevant to the spread of the virus, drawing upon four sources: (1) relevant evidence and recommendations from the Scientific Pandemic Influenza Group on Behaviours produced for the Scientific Advisory Group for Emergencies (SAGE); (2) research evidence from non-pandemic conditions; (3) research on behaviour during the pandemic; and (4) relevant theory. We first outline some basic risks and a framework for understanding collective behaviour at live events. We then survey some trends in UK public behaviour observed over 2020 and how these might interact with the opening of live events and venues. We present a range of mitigation strategies, based on the framework for collective behaviour and on what is known about non-pharmaceutical (i.e. behavioural) interventions in relation to Covid-19.

Correction: The impact of believing you have had COVID-19 on self-reported behaviour: Cross-sectional survey.

[This corrects the article DOI: 10.1371/journal.pone.0240399.].

The impact of believing you have had COVID-19 on self-reported behaviour: Cross-sectional survey.

OBJECTIVES: To investigate whether people who think they have had COVID-19 are less likely to report engaging with lockdown measures compared with those who think they have not had COVID-19. DESIGN: On-line cross-sectional survey. SETTING: Data were collected between 20th and 22nd April 2020. PARTICIPANTS: 6149 participants living in the UK aged 18 years or over. MAIN OUTCOME MEASURES: Perceived immunity to COVID-19, self-reported adherence to social distancing measures (going out for essential shopping, nonessential shopping, and meeting up with friends/family; total out-of-home activity), worry about COVID-19 and perceived risk of COVID-19 to oneself and people in the UK. Knowledge that cough and high temperature / fever are the main symptoms of COVID-19. We used logistic regression analyses and one-way ANOVAs to investigate associations between believing you had had COVID-19 and binary and continuous outcomes respectively. RESULTS: In this sample, 1493 people (24.3%) thought they had had COVID-19 but only 245 (4.0%) reported having received a positive test result. Reported test results were often incongruent with participants' belief that they had had COVID-19. People who believed that they had had COVID-19 were: more likely to agree that they had some immunity to COVID-19; less likely to report adhering to lockdown measures; less worried about COVID-19; and less likely to know that cough and high temperature / fever are two of the most common symptoms of COVID-19. CONCLUSIONS: At the time of data collection, the percentage of people in the UK who thought they had already had COVID-19 was about twice the estimated infection rate. Those who believed they had had COVID-19 were more likely to report leaving home. This may contribute to transmission of the virus. Clear communications to this growing group are needed to explain why protective measures continue to be important and to encourage sustained adherence.

'Immunity Passports' for SARS-CoV-2: an online experimental study of the impact of antibody test terminology on perceived risk and behaviour.

OBJECTIVE: To assess the impact of describing an antibody-positive test result using the terms Immunity and Passport or Certificate, alone or in combination, on perceived risk of becoming infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and protective behaviours. DESIGN: 2×3 experimental design. SETTING: Online. PARTICIPANTS: 1204 adults from a UK research panel. INTERVENTION: Participants were randomised to receive one of six descriptions of an antibody test and results showing SARS-CoV-2 antibodies, differing in the terms describing the type of test (Immunity vs Antibody) and the test result (Passport vs Certificate vs Test). MAIN OUTCOME MEASURES: Primary outcome: proportion of participants perceiving no risk of infection with SARS-CoV-2 given an antibody-positive test result. Other outcomes include: intended changes to frequency of hand washing and physical distancing. RESULTS: When using the term Immunity (vs Antibody), 19.1% of participants (95% CI 16.1% to 22.5%) (vs 9.8% (95% CI 7.5% to 12.4%)) perceived no risk of catching coronavirus given an antibody-positive test result (adjusted OR (AOR): 2.91 (95% CI 1.52 to 5.55)). Using the terms Passport or Certificate-as opposed to Test-had no significant effect (AOR: 1.24 (95% CI 0.62 to 2.48) and AOR: 0.96 (95% CI 0.47 to 1.99) respectively). There was no significant interaction between the effects of the test and result terminology. Across groups, perceiving no risk of infection was associated with an intention to wash hands less frequently (AOR: 2.32 (95% CI 1.25 to 4.28)); there was no significant association with intended avoidance of physical contact (AOR: 1.37 (95% CI 0.93 to 2.03)). CONCLUSIONS: Using the term Immunity (vs Antibody) to describe antibody tests for SARS-CoV-2 increases the proportion of people believing that an antibody-positive result means they have no risk of catching coronavirus in the future, a perception that may be associated with less frequent hand washing. TRIAL REGISTRATION NUMBER: Open Science Framework: https://osf.io/tjwz8/files/.