Why you need to know more than just the relative risk.

Adulting can be tricky. We need to make lots of hard decisions that perhaps we’d rather not have to. We have to weigh up the pros and cons of each choice carefully to make a nuanced and appropriate decision each time.

Which house? Which pension? Which gym? Which job? Which dinner??...And sometimes we just wish that we can regress and have someone else figure it all out for us.

When pregnant these decision making processes grow larger.

Which hospital? Which setting? Which buggy? Which house? Which cot? Which chair? Which plan?

Then 40+ weeks…. Which induction?…

For nearly all women in the UK, US and Aus who go past a certain date without having had their baby the induction question will come up. And this is an adulting decision that you do not wish to pass on to someone else.

Induction of labour may well be the right decision for you or may well be the wrong decision for you, but you will need to peel back the layers of this subject to truly understand it. Starting with the difference between Relative Risk and Absolute Risk.

These are two ways of looking at and understanding the same figures.

For example - Do I become a vegan for better health?

Well the Relative Risk of getting bowel cancer from eating processed meat is 18% higher than if I avoided processed meat entirely. That seems rather risky and sounds bad enough for me to change. But what are the actual figures? If 56 people out of a 1000 will get bowel cancer but of those that eat processed meat it is 66 people out of a 1000. Then the Absolute Risk of a rise from 5.6% to 6.6% is only 1%.

Hmmm….

So the Absolute Risk of bowel cancer in processed meat eaters goes up by just 1% according to those stats.

But what of variables? Well, of those in both camps should we not take into account fitness levels? Diversity of diet? General health? Whether they had cancer before? If cancer is prevalent in their family? Age? Mental health? Lifestyle choices?

And this is the problem with certain statistics.

If the Absolute Risk of being run over by the 319 bus is 2 in 100 and there is a 50% increase, well that only takes us to 3 in 100. But when we say a 50% increase or that your chances of something happening has doubled we tend to lose sight of the Absolute Risk figure at the end. And would this figure be changed by rain or fog or broken street lights or speed restrictions? Would crossing be worth it if the only supermarket available is on the other side of the street?

So when induction of labour is discussed the figures that you want to speak about are the Absolute Risk figures not the Relative Risk figures. You also then need to factor in your own individuality (weight, fitness, how many previous births, general health) to be able to make a clear decision on what you are being offered.

And finally. If I buy a lottery ticket this week I am increasing my odds of winning by 100% having never bothered to buy one before. Wow! Better get one then!

But what are my actual chances of winning? 14 million to 1.

Oh well.