Understanding Health Risk

Posted: 26th January 2011

Hands up if you play the National Lottery. I ask this question in many of my workshops and it always sparks an interesting conversation. The lottery is a great demonstrator for how we interpret odds and chance. The odds of winning the jackpot on a Saturday draw is less than 1 in 14 million. There are over 14 million different combinations of 6 numbers than can come from the draw. Given that there are many more than 14 million lines of lotto numbers bought for each Saturday, there is a high chance (although not guaranteed) there will be at least one winner each week.

If we really understood what the chances are of winning the jackpot, I think it’s very unlikely as many of us would play it. In fact, if you bought a ticket for a Saturday draw any earlier than 36 hours before it closed, the odds are greater you’d be dead before the draw took place than for you to win the jackpot. Our brains don’t handle the big numbers; 14 million is a lot, but so is 150,000, or 10,000. Our internal computers know the chances are small but we struggle to grasp actually just how remote the winning probability is.

We’ve also read about lotto winners and how the windfall has changed their lives and the lives of the people around them. They are people like us and we reason that if people just like us can win the jackpot then so can we. The giant “IT'S YOU” God-like hand in the lotto adverts was a stroke of genius as it made us all feel that the possibility of winning was higher than it really was.

Think about the mainstay of health improvement messages that are driven out to the public in the UK. Most of them are wrapped up in numbers and future health risk percentages. For example, “did you know that in Wales, 10,000 people each year die from CHD. If you increase your physical activity levels to 5 x 30 minutes each week, you will reduce the risk of developing...” and then we reel off all the relative percentage risks of developing lurking nasty diseases and conditions that we would be exposing ourselves to by being inactive.

I see these messages all the time, numbers-based, rational arguments for why people should make changes to their behaviour. The problem is that behaviour change is hard. It requires breaking down old habits and routines and creating new ones. I meet very few people who decide to take on the effort to change their lifestyles based on logical fact. Mostly these decisions are emotionally driven, such as unhappiness at being overweight or frustrated by feeling unfit or determination to stop allowing the cigarettes to control their impulses.

There are two sides to our brains; firstly there’s the calm, logical, processing, rational brain and then there’s the emotional, subconscious, irrational supercomputer brain. We can’t be in the domain of both at the same time. The idea of a Lotto win strikes an emotional chord in us and appeals to the subconscious brain. The calculation of the probability of a win happening sits with the logical brain. At the time we buy our lotto ticket, fueled by the hope and excitement of a potential win, the logical brain has no chance.

The use of rational figures and health risk arguments is to put people in a position of fear. If we can scare them into realising that their existing lifestyle can cause themselves long-term harm we reason that their fear will drive them to change. However, as a behaviour-change tool, fear only works if people are actually afraid of the picture we are painting for them. Not only do they have to be afraid of the possible outcome (cancer, CHD, diabetes, poor quality of life etc.) but they also have to believe they have a solid chance of developing it.

The fear argument is diluted by a string of beliefs that people have when it comes to health improvement. There are “faults” in the way we subconsciously process information, known as cognitive biases. You may have heard examples of these at play if you have ever heard people uttering the following statements:

What goes around comes around. (Subtext = I’m a nice person so it’s unlikely I’ll come to any harm).
Well I feel ok now (Subtext = it can’t be doing me much harm).
My great uncle Bertie lived to be 96 and he smoked 40 a day (Subtext = longevity runs in the family and here’s an example of someone who didn’t suffer a day from smoking).
My friend’s boyfriend dropped dead playing football (Subtext = isn’t being active more dangerous).
It won’t happen to me. (Subtext = I hear what you’re saying but I expect to be one of the % of people who don’t get it)
They say you can reverse all the damage from smoking so I’ll give up when I’m older. (Subtext = I’ll quit when I feel like it and there’ll be no future health consequence for me)
I’m a careful driver. (Subtext = accidents only happen to bad drivers so I’ll be ok).
Life’s short so you might as well enjoy yourself. (Subtext = I don’t want to quit smoking and I want to make myself feel better about it)
I might get knocked down by a bus tomorrow (Subtext = don’t give me stats I don’t understand).

The fear messages aren’t causing them a significant amount of trouble and it’s easy to find an argument that will defend their position to carry on as they are. Looking at the statistics, most of the time they are right. While the risks of future ill health might increase for a given unhealthy behaviour, such as smoking, the odds are still on their side. A person who leads a sedentary life is still most likely to be completely fine, even if their risk of ill health increases.

Here’s an example:

Research shows that leading an active lifestyle can reduce the risk of developing (any) cancer by 40-50%.

UK cancer statistics show the annual incidence of all types of cancer to be approximately 300,000 new cases with a 52% average survival rate at present (although the survival rate varies depending on cancer type). This represents approximately a 1 in 325 chance of developing terminal cancer in a given year. This would represent a 1 in 16 chance across a span of 20 years. We are hoping to persuade people to increase their activity levels to 5 x 30 minutes each week, indefinitely, which is a huge ask and in return they will reduce their chances of dying from cancer by 1 point in 32, when they already have a 2 points in 32 chance of developing it anyway.

Across a population, the figures are startling. On an individual basis the odds are stacked in favour of cancer-free future, with or without an active lifestyle.

The bottom line is that we should stop using health risk statistics as our key argument to try and persuade people to change their behaviour. We’ve been doing it for decades and it clearly does not work. People aren’t in a cold rational place when they decide to change their lifestyles and they can’t feel fear and be calm and logical at the same time so the numbers on their own won’t influence change. Besides, if people really did understand the numbers, they probably wouldn’t be afraid of them anyway.

So what should we do instead? In my opinion, heap on the immediate, guaranteed, positive and personal benefits for the lifestyle change. Talk about the wonderful things they will experience as a result of their behaviour change, and not in the context of decades, but in how they will feel next week or next month. Talk about the things they will definitely see, such as more energy, or better quality sleep or more money in their pocket, rather than the things that may or may not happen.

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