Elsevier

Vaccine

Volume 23, Issue 23, 27 April 2005, Pages 3010-3015
Vaccine

Changing attitudes towards polio vaccination: a randomized trial of an evidence-based presentation versus a presentation from a polio survivor

https://doi.org/10.1016/j.vaccine.2004.12.002Get rights and content

Abstract

We compared the impact of epidemiological evidence and anecdotal evidence on changing vaccination attitudes amongst alternative medical students. Ninety-seven students were randomized to either an evidence-based lecture on the benefits of the polio vaccine on population health or a presentation from a visibly affected victim of polio. We compared change in responses to a survey measuring vaccination attitudes between the two groups. The follow-up rate was 73%. There was no statistically significant difference between the two groups in change in response to any of the survey questions. In a post hoc analysis we found that 25% of students were less likely to recommend the vaccine after being provided with evidence supporting vaccination. These findings suggest that confronting deeply held beliefs regarding vaccination may paradoxically strengthen these belief systems.

Introduction

Concerns about pediatric vaccinations amongst some individuals remains a persistent challenge to public health officials interested in ensuring high vaccination rates [1]. Efforts to improve vaccination have largely centered on education programmes designed to inform the public of the benefits and safety of vaccines [2], [3], [4]. However, despite these efforts some individuals have remained highly skeptical about the safety and efficacy of vaccines. Public health officials have partially attributed this to the fact that the diseases being vaccinated against are no longer present, largely due to the success of the vaccine programmes [5]. The argument has been made that if these individuals had seen the illnesses these vaccines are designed to prevent they would not harbour such strong anti-vaccination views.

We sought to test the hypothesis that anecdotal evidence in the form of an individual with a vaccine preventable disease would be more effective than an evidence-based presentation in persuading populations of the benefits of vaccines [6]. We specifically tested this hypothesis as it related to the polio vaccine. Our belief that seeing a survivor of polio would be more effective than evidence in influencing attitudes was based on the “vividness hypothesis” [7]. According to this hypothesis vivid information, in the form of a well-described anecdote or a recent clinical experience, is more persuasive than pallid information, such as epidemiological data. This hypothesis, as it pertains to vaccination attitudes, was supported by a previous survey we conducted which identified a negative association between personal knowledge of a patient with an adverse vaccine reaction and willingness to advise vaccination [8].

To specifically test our hypothesis we conducted a trial in which we randomized alternative medicine students, who had previously been documented to harbour views less supportive of vaccination, to receive a primarily epidemiological lecture on the benefits of the polio vaccine or to hear the experiences of a polio survivor [8]. We examined the change in attitudes towards vaccination as measured by change in before-and-after survey responses in each of these two groups.

Section snippets

Study population

Our study population was the final year students at a large Canadian alternative medicine school. Students were informed at the beginning of class that a study was being conducted and they could choose to participate by completing a survey before and after having heard a presentation on vaccinations. Students had received an identical education over the previous three years in CAM modalities, philosophy and sciences. The school does not have a formal opinion on vaccines, however, vaccine

Results

In total 97 students chose to participate and filled out the pre-presentation survey. Our final sample consisted of 71 students who completed both the pre and post surveys, with 41 individuals in the polio survivor group and 30 individuals in the evidence group. The follow-up rate was 73%. The groups were similar demographically except that Group A had a higher proportion of single students (Table 1). Our baseline data confirmed our starting hypothesis that this population was generally

Discussion

In this study of individuals randomized to an evidence-based presentation or a presentation of anecdotal evidence to influence their attitudes on the polio vaccine we found that, as an aggregate, neither intervention had a statistically significant effect on vaccination attitudes. However, when examining the results more closely we were surprised to observe that some students were less supportive of polio vaccination after being provided with pro-vaccination information.

There are several

Conclusion

Changing vaccination attitudes amongst those who have strongly held belief systems is a challenging process. Simple delivery of evidence, either in the format of a vivid example or as an evidence-based presentation may, in some individuals, reinforce their concerns about vaccination. We recommend further exploration of alternative approaches to addressing this issue that are more respectful and less threatening to belief systems. These approaches will likely involve mechanisms to improve trust

Acknowledgements

Dr. Wilson is supported by a Canadian Institutes of Health Research New Investigator Award. This study was supported by funding from the Canadian Naturopathic Foundation and the Canadian Institutes of Health Research.

References (13)

There are more references available in the full text version of this article.

Cited by (44)

View all citing articles on Scopus
1

Kumanan Wilson and Edward J. Mills to be considered equivalent authors.

View full text