Additional survey among physicians
To collect feedback from physicians on COVID-19 vaccines, we conducted a survey in partnership with the CMC to maximize coverage of the medical community. The survey was conducted online in February 2021. Because CMC membership is mandatory, the CMC has a contact list for all doctors in the country. The CMC contacted all physicians associated with the CMC electronically (70%) and asked them to participate in a short survey using the Qualtrics platform. 9,650 (24%) of the contacted physicians responded to the survey. In all regions of the country, the average age of our doctors is 52 years, 64% are women and 62% have more than 20 years of experience. A comparison of the characteristics of our sample physicians and all physicians in the Czech Republic is given in Table 1.
Our main model consisted of 2,101 participants in a long online data collection, Life in a Pandemic, organized by the authors in collaboration with PAQ Research and the NMS survey agency. In March 2020, the commission began providing real-time data on developments in economic, health and social conditions during the COVID-19 pandemic. We used data from 12 consecutive data collection waves conducted at intervals of 3-4 weeks from mid-March to the end of November 2021.
The intervention information was implemented on March 15, 2021, and we marked it as a 0 wave. Wave pattern 0 “base pattern” (do not= 2,101, 1,052 female participants and 1,049 male participants, mean age 52.9 years (sd = 15.98), youngest 18 years old, oldest 92 years old). The basic model is a broad representation of the adult population of the Czech Republic in terms of sex, age, education, region, size of municipality, employment status before the COVID-19 pandemic, age × sex and age × education. The choice of Prague and municipalities with a population of more than 50,000 is very high (200% increase). Sample statistics are given in the Advanced Data Sheet 1. The selection is close to that of the Czech adult population in relation to the COVID-19 vaccine. The development of the proportion of people vaccinated under control is very similar to the current rate of vaccinations in the Czech Republic (Extended data Figure 1), when we weighed the sample observations to be representative of the observable characteristics.
An important feature of the panel is that participants agreed to be interviewed regularly and the response rate was high throughout the study: it ranged between 76% and 92% in individual follow-up waves and 86% for the last wave, implemented in late November 2021. 1212 participants (58%) participated in all 12 waves of data collection: they form a “sustainable model”. Therefore, in the analysis, we report the main results for all participants in the base model who responded to (1) the given wave, which we refer to as the “complete model” and eliminated the role and facilitated the measurement of the dynamics of therapeutic effects.
In Wave 0, participants were randomly assigned to a consensus condition (do not= 1,050) or Management Condition (do not= 1,051). Under the consensus, they learned that the CMC conducted a large survey of about 10,000 doctors from all over the country to gather feedback on COVID-19 vaccines. It was also noted that the views of doctors of different genders, ages and regions are similar. Participants were then shown three diagrams showing their confidence in vaccines, their willingness to be vaccinated, and their responses to recommending the vaccine to their patients. Each of the charts is supplemented by a brief resume. Detailed wording and diagrams are provided in Section 3.3 of the Additional Information. In the control condition, participants did not receive any information about the doctor’s survey.
Prior to the information intervention on Wave 0, we identified previous beliefs about the physician’s views in order to quantify the misconceptions about physicians ’opinions. In particular, participants were asked to calculate (1) the percentage of doctors who believe in vaccines approved in the Czech Republic and (2) the percentage of doctors who have received or intend to be vaccinated. Later, in Wave 1, we found backlinks to determine whether consensus-based people had renewed their beliefs based on the information provided by physicians. In each of the 12 waves, we asked respondents to report whether they had been vaccinated against COVID-19. If the respondent reported receiving at least one dose of the COVID-19 vaccine, the main outcome variable was the same as the “vaccinated” one.
In the analysis, we specify two main regressions: (1) control linear probability regression for pre-registered covariates: gender, age (6 categories), household size, number of children, area (14 areas), city size (7) categories), education (category 4), economic status (category 7), household income (category 11) and intention to pre-vaccination, and (2) LASO linear regression, including pre-vaccination, which selected a broad set of controls in Table 1 beliefs about vaccine intake and physicians ’views.
Additional information to check the status of vaccination
We collected two sets of additional data to verify the status of the reported vaccination in the main data set.
Third Party Verification
First, we used data collected by a third party, an independent party. We took advantage of the fact that various survey agencies had access to a panel selected by our respondents (Czech National Panel). Although the basic data collection was carried out by one agency (NMS), we partnered with another agency (STEM / MARK) to include the question of vaccination status in a sample survey on its behalf. Because the survey agency, graphical interface, and survey topic are different from our primary data collection, respondents believe that the two surveys are completely independent of each other, so the experimenter does not play a role in the second survey. The response rate was high (92.8%) and treatment-independent (Extended Data Table 6). Of the 1,801 participants in the 11th wave, 1,672 also took part in a third-party verification survey conducted two weeks later. This allowed us to compare the reported vaccination status at the individual level for the vast majority of our sample and to see if it affected the level of consistency of vaccination reporting consistency in Consensus surveys.
The second test links the status of the vaccine to the official evidence of vaccination. We used all vaccinated people to obtain an EU Digital COVID certificate issued by the Czech Ministry of Health. We collected data on vaccination certificates from respondents who (1) participated in wave 11 and (2) had at least one dose of COVID-19 in wave 11.do not= 1.414). We asked respondents if they had a certificate. 96% of the participants confirmed that they have a certificate and this proportion is very similar in terms of Consensus and Control (χtwo(1,do not= 1,414) = 0.999, P= 0.318). Certified recipients were asked to provide some specific information about the vaccine that is unlikely to be available to anyone without a certificate (for example, the correct answer for vaccine recipients from Pfizer / Biontech: “SARS-” CoV-2 mRNA ‘). Evaluation of the typed text by independent evaluators shows that more than 94% of respondents actually reviewed the certificate while answering our detailed questions, provided they have a certificate. This figure is very similar in terms of more conditions (χtwo(1,do not= 1.364) = 0.473, P= 0.492).
More information on inspection procedures and results can be found in the Appendix.
affirmation of ethics
The study was approved by the Ethics Commission for Research at Charles University’s Faculty of Social Sciences. Participation was voluntary, and all respondents agreed to participate in the survey.
Additional information on the design of the study is available in the summary of the Nature Research Report, which is referenced in this paper.