Mistaking Subsequence for Consequence

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.

It is incident to physicians, I am afraid, beyond all other men, to mistake subsequence for consequence.

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.”

Because polio outbreaks often came in summer months, some folks thought the virus must be spread at swimming pools, so they were often closed. It didn't help... Correlation did not equal causation.
Because polio outbreaks often came in summer months, some folks thought the virus must be spread at swimming pools, so they were often closed. It didn’t help… Correlation did not equal 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

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.