5

When opinion trumps evidence, public health is at risk

In an era when belief in an opinion is treated as a legitimate form of evidence, real evidence-based medicine is more important than ever


 

A woman holds the hand of her mother who is dying from cancer during her final hours at a palliative care hospital in Winnipeg

This article originally appeared on The Conversation. logo-6ed98023442246a1b432bd646eec8daf94dba5361825aeacd7d7ca488c268e96

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.

A baby crying and leaning on her mother's shoulder. (Carey Kirkella/Getty Images)

A baby crying and leaning on her mother’s shoulder. (Carey Kirkella/Getty Images)

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.

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.

Nicole Letourneau is a professor in Nursing & Medicine, and the ACHF Chair in Parent-Infant Mental Health at the University of Calgary.

The Conversation


 
Filed under:

When opinion trumps evidence, public health is at risk

  1. This far from an American phenomenon.

    Consider these current issues.

    Despite proof that marijuana use has been proven to cause mental illness, Trudeau wants to legalize it.

    Despite the fact that gender dysphoria is a mental disorder, Wynne banned successful conversion therapy.

    Despite DNA fingerprinting science that proves a fetus is a living unique human individual, more than half of all pregnancies in the GTA are terminated by killing the baby in abortion.

    The list goes on.

    • Here’s a perfect example of ignorance

    • Actually, the science has found correlations between cannabis use and mental illness. Correlation does not equal causation. The correlations are due, in part, to people with mental illnesses self-medicating with cannabis. Science has also found that cannabis chemovars which are high in THC but low in CBD and some important terpenes can trigger psychosis in vulnerable individuals, but we would need to prevent about 23,000 teens from consuming cannabis to prevent one case of cannabis-triggered psychosis. Black market cultivators favour strains that are high in THC but low in CBD and they do not put potency levels or warning labels on their sandwich baggies. Trudeau wants to legally regulate cannabis, in part, because it can be bad for the mental health of teenagers.

  2. “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.”

    Actually, concerns about immature brains are leading the conversation. See for example the recent CMAJ editorial on the subject. The problem is that we can not craft the optimal (not utopian) regulatory model for cannabis by looking at MRI scans.

    Currently Canadian teens consume the most cannabis in the industrialized world, they find cannabis easier to obtain than alcohol, they are about twice as likely to try cannabis than try tobacco and their average age of initiation is 14.

    The more dangerous the substance, the less it makes sense to abdicate control over it to criminals who sell myriad drugs of unknown potency, purity and provenance, on commission, tax free, to anyone of any age, anytime, anywhere, no questions asked.

    The task force that recommended 18 as a federal minimum also considered the harm criminal records cause to young people, something “EBM” fails to address.

Sign in to comment.