We don't usually think about risk consciously when we do something. By consciously I mean pause and consider how likely there will be a bad result to something we do.
For instance, do you consider the risk of driving somewhere in a car? What chance is there of dying? In the USA the risk of dying in a car in a 230 mile (370Km) is 1 in 1,000,000. Think Christchurch to Mosgiel.
A micromort is a really useful way of thinking about risk, and was introduced by Ronald A Howard in the early 80s.
The picture on the right contains 50,000 icons of a person . You can see the full size picture here.
So what does a micromort look like? We'll represent a micromort with a skull icon .
Going back to the driving to Mosgiel example. 1 micromort is 1 skull icon in 20 pictures like the one on the right. Here's another representation of a micromort. There's one skull in the top left hand corner, and then another 19 pages of the little human icon.
1,000,000 icons / 50,000 icons per page = 20 pages
Just knowing how risky driving a car is doesn't really help you understand much. We need to compare that risk with other risks.
So here we go, some other things that have a 1 micromort risk associated with them.
As you can see there are some things in that list that you would expect, and accept have a risk associated with them. I hadn't really every considered the risk of going for a walk for 20 minutes, I certainly wouldn't have thought it carried the same risk as flying from Whangarei to Dunedin.
Those risks are all pretty small. What else have we got
Around 10 micromorts
Around 100 micromorts
Even more dangerous
So now we can start to compare different activities. Running a marathon is 7 times as risky as going for a 20 minute walk. Scuba diving is only half as risky as having an operation where you have a general anaesthetic. Being born may be the riskiest thing you ever do in your life at 430 micromorts.
Professor David Nutt used the idea of a micromort to illustrate relative risk of drug use - a move that was very risky for his career. Prof Nutt compared taking Ecstasy (MDMA) and horse riding and concluded that they were very similar - about half a micromort each.
At the moment there is only really one thing people are worried about when it comes to risk Covid 19. So how many micromorts does having a Covid 19 infection carry? Using global data the mortality rate of Covid 19 is just north of 2%. So 2 out of every hundred people infected die from Covid-19. So what's that in micromorts.
1% is equvialent to 10,000 micromorts 2% = 20,000
Here's the maths : 1,000,000 *.01 = 10,000
From that maths the risk of dying from a covid infection is
So you would have to ride a motorcycle for 100,000 Km to have the same risk of dying as you would from a Covid-19 infection.
Here's the maths :
Vaccine risk is the next thing on people's mind. There has been a great deal made of vaccine side effects. And yes all vaccines do have side effects, including Covid-19 vaccines. The important thing is that they are much less risky than getting Covid-19 itself. There has been much made in the news of a rare, but not new, side effect of the AstraZeneca vaccine vaccine-induced prothrombotic immune thrombocytopenia (VIPIT). It's being openly and vigorously debated in the biological scienctists, so nobody is denying it exists. There have only been 15 reported deaths out of 17 million people being vaccinated in the UK and Europe. That's about 0.000088%
Here's the maths:
15 events /17,000,000 vaccinations given
*100 = 0.000088% (or if you prefer 1 case per 1,133,333 people vaccinated, or roughly 4 cases in the population of NZ)
Back to the micromorts
So if 1% equals 10,000 micromorts
Then the risk of dying from VIPIT is 1/1.133
Remember the risk of dying from a covid infection from before. I'll remind you
As you can see the risks are hugely different.
Or another way
Get your Covid vaccination when you are offered it.