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Public health at risk when opinion trumps evidence

Dozens of studies and numerous reviews have demonstrated the safety of vaccines. (Shutterstock)

In the Trump era, we have seen dramatic reductions in dialogue on important issues of the day. We have seen attacks on the legitimacy of science. We have seen attacks on trusted news sources, derided as fake. On social media, one person’s opinion, whether expert or not, often seems to outweigh all other forms of evidence. Belief in an opinion is treated as a legitimate form of evidence. For many people today, beliefs about vaccination or breastfeeding or marijuana inform everyday important decisions that affect their health and the public’s health.

This is dangerous.

Many historical examples show that beliefs can lead us astray. At one time, most people believed that the Earth was flat and if you sailed too far west, you would fall off. To counter such beliefs, we created processes like the scientific method and more recent approaches to evidence evaluation that help to ensure that the best evidence informs thinking and decisions.

Nurses, physicians and other health professionals learn about evaluating evidence in their basic education — it’s called evidence-based medicine (EBM). In my role as Professor and Alberta Children’s Hospital Foundation Chair in Parent-Infant Mental Health at the University of Calgary in Alberta, I have taught countless students about EBM.

Public policies based on evidence

EBM draws upon systematic review and assessment of bias to help evaluators make judgements about the quality of evidence. Once judgements are made, recommendations can be designed to improve health. EBM also takes context into account. There is a recognition that recommendations from EBM may not be applicable to everyone. EBM is also open-minded, as new evidence should always be considered and add insight that can change recommendations.

Countless public health policies have derived from this approach. Recommendations on Vitamin D administration to promote healthy bone growth in babies, aspirin intake for stroke prevention in adults, and pap screening for cancer prevention in women are but a few examples. But today, EBM approaches are under threat. For most people, findings from one study or hearing an opinion of an expert on a topic are enough for beliefs to form.

Name-calling and divisive tactics

Breastfeeding, legalization of marijuana and vaccination are important public health issues that require EBM approaches. But instead, name-calling and divisive tactics rule the day. Often, “anti-vaxxers” accuse those who disagree of being in the pocket of “Big Pharma.” Public health officials who promote breastfeeding are accused of bullying. Camps form comprised of the “breast is best” advocates who are called “breastfeeding bullies” by the “fed is best” advocates. These tag lines or hashtags function as banners for proponents to get behind or oppose. Camp dwellers put down stakes and put up their tents and there seems to be no way to move either side.

An overwhelming majority of evidence, reviewed by the World Health Organization, generally shows that breastfeeding is good for babies and mothers’ health. Thus, health-care providers recommend and promote breastfeeding as a public good. EBM suggests that, of course, there are situations where mothers and babies cannot breastfeed and for whom we should show compassion. EBM is about what’s best for most people, not everyone. Recognizing that EBM allows exceptions would prevent camps from forming and encourage understanding of nuance and context. But the camps have dug in.

Debate rages over public health issues like breastfeeding. (Shutterstock)

Lots of evidence shows that marijuana is not good for people’s brains less than 25 years of age, which are still forming and more sensitive than older brains. While sides of the debate are not encamped (yet), EBM is not leading the discussion. Rather, the focus is on the difficulty of policing the laws for teenagers and young adults. The conversation goes like this: Teens and young adults are smoking marijuana anyway while it’s illegal, so does it matter what the lower age limit is? Public health policy, led by EBM, would say yes, it does matter very much.

Dozens of studies and numerous reviews have demonstrated the safety of vaccines. Evidence shows the benefits far outweigh the risks. The dramatic decline in babies catching common childhood diseases that used to kill them is evidence enough to support the public good of vaccination. This is perhaps the most extreme example, because the evidence base is strong. Nonetheless, opponents will accuse the pharmaceutical companies of unethical gains from the use of vaccines, effectively shutting down the reasoned dialogue that we need, much less consider the special contexts when vaccination should not be used.

Each of these issues has evidence to support opposing camps. However, the use of EBM enables a more informed and nuanced understanding to inform healthy public policy and protect and promote health. The problem with the opposing arguments is that they ignore evidence and they ignore context – tenets of EBM.

Protecting the public

The confusion of the Trump era, fraught with division and distrust fostered by the avalanche of information on social media, could be reduced by giving members of the public the tools they need to evaluate evidence.

Understanding and using the tenets of EBM would reduce the likelihood that people would make dangerous decisions about their health practices. Thus, policy makers both federally and provincially should recommend investment in EBM education and marketing campaigns established to educate the population about EBM as a public good. Then EBM would cease to be endangered and the public would be protected from dangerous, poorly informed beliefs and lack of compassion for people’s individual contexts.

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