Most parents understand that vaccines are safe, with few risks, and necessary, but some are still scared to get their kids vaccinated and protected.
Some even get anxious at the idea of going to their next visit to their pediatrician, because it might mean their baby is going to get shots.
Why?
They have likely heard some of those vaccine injury stories and got to thinking – how could all of those parents be wrong?
Mistaking Subsequence for Consequence
It’s easy to make a hasty judgement about something.
We jump to conclusions and try to link things together when they occur at about the same time as each other.
That’s because we often mistake subsequence (the state of following something) for consequence (a result of an action).
For example, developing multiple sclerosis (the consequence) six weeks after (subsequent) getting a vaccine, doesn’t mean that the vaccine caused you to develop multiple sclerosis.
Although the source of the quote on subsequence and consequence is Dr. Samuel Johnson, an 18th century writer, it got new life when Justice Jeremy Stuart-Smith used it in a DTP vaccine trial verdict.
“Where given effects, such as serious neurological disease or permanent brain damage, occur with or without pertussis vaccination, it is only possible to assess whether the vaccine is a cause, or more precisely a risk factor, when the background incidence of the disease is taken into account. The question therefore is, does the effect occur more often after pertussis vaccination than could be expected by chance?”
Sir Jeremy Stuart-Smith
What about chance and coincidences?
Instead of thinking that things could simply be the result of chance or a coincidence, we typically want more of an explanation when something happens, and sometimes, we simply want someone or something to blame.
“Establishing or disproving cause and effect, particularly for events of major consequence, proved difficult. Although the original allegations of causation were largely anecdotal and based on the fallacious assumption that subsequences and consequences were synonymous, they raised great concern and stimulated the search for an improved vaccine.”
Vaccines (Seventh Edition)
That leads us to fallacious thinking – post hoc ergo propter hoc (after this, therefore, because of this).
It shouldn’t though.
“Most of you will have heard the maxim “correlation does not imply causation.” Just because two variables have a statistical relationship with each other does not mean that one is responsible for the other. For instance, ice cream sales and forest fires are correlated because both occur more often in the summer heat. But there is no causation; you don’t light a patch of the Montana brush on fire when you buy a pint of Haagan-Dazs.”
Nate Silver
Remember, “correlation does not imply causation.”
That maxim becomes easier to understand when you see all of the things that correlate together, like ice cream sales and forest fires, but once you think about them, there is no way that one could cause the other.
- the consumption of high fructose corn syrup and deaths caused by lightning
- the divorce rate in Maine and the per capita consumption of margarine
- autism rates and organic food sales
- autism rates and Jenny McCarthy‘s popularity?!?
Correlation does not imply causation.
“It is incident to physicians, I am afraid, beyond all other men, to mistake subsequence for consequence.”
Dr Samuel Johnson
Fortunately, it is not as “incident to” (likely to happen to) physicians these days to “mistake subsequence for consequence.”
There are certainly some vaccine friendly pediatricians who pander to the fears of parents and push so-called alternative, non-standard, parent-selected, delayed protection vaccine schedules, who seem to believe in anecdotal evidence above all else, but most doctors understand that vaccines are safe and necessary.
They also know that because correlation can sometimes equal causation, we don’t ignore possible vaccine injuries. And that’s why we have strong vaccine safety systems that can detect and warn us of true vaccine risks.
More on Mistaking Subsequence for Consequence
- VAXOPEDIA – Explaining the Correlation of Autism After Vaccines
- VAXOPEDIA – Correlation and Causation
- VAXOPEDIA – Vaccine Injuries vs Coincidences
- VAXOPEDIA – Is It a Vaccine Reaction?
- Spurious Correlations
- A lesson about correlation and causation
- Basic Statistics Part 2: Correlation vs. Causation
- Autism and Vaccines: Correlation is Not Causation
- Spurious Correlations
- What do Ice Cream, Cats, and The Subway Have in Common? A Big Polio Mistake.
- Polio and Swimming Pools: Historical Connections
- When can correlation equal causation?
- How Coincidences Shape Views of Vaccines–and Shouldn’t
- Evidence in Medicine: Correlation and Causation
- Clearing up confusion between correlation and causation
- A lesson about correlation and causation
- Repeat after me: “Correlation does not imply causation”
- The Top Five Most Annoying Statistical Fallacies
- Study – Use of population based background rates of disease to assess vaccine safety in childhood and mass immunisation in Denmark: nationwide population based cohort study
- Study – Probability of coincident vaccination in the 24 or 48 hours preceding sudden infant death syndrome death in Australia.
- Study – Algorithm to assess causality after individual adverse events following immunizations
- Vaccine Causality Algorithm
- Study – Assessment of causality of individual adverse events following immunization (AEFI): a WHO tool for global use.
- Why are there so many reports of autism following vaccination? A mathematical assessment
- Study – Reanalyses of case-control studies examining the temporal association between sudden infant death syndrome and vaccination.
- WHO – Six common misconceptions about immunization
- Study – Baseline incidence of intussusception in early childhood before rotavirus vaccine introduction, the Netherlands, January 2008 to December 2012
- Post hoc, ergo propter hoc
- Post hoc fallacy
- Correlation and Causation
- Study – Deaths following influenza vaccination—background mortality or causal connection?
- Study – Importance of background rates of disease in assessment of vaccine safety during mass immunisation with pandemic H1N1 influenza vaccines
- Properly evaluating vaccine mortality – let’s not abuse VAERS
- Study – Deaths following vaccination: What does the evidence show?
- Study – Mortality rates and cause-of-death patterns in a vaccinated population.
- Dr. Anthony Fauci: Risks From Vaccines Are “Almost Nonmeasurable”
- Study – A risk-benefit analysis of vaccination.
- Causation and Hill’s Criteria
- Evidence in Medicine: Correlation and Causation
- Statistics for Skeptics Part 2 – Correlation vs. Causation