The Fun Index: What level justifies the use of trampolines?

A decade ago the number of trampoline injuries was described as an ‘epidemic’ by some commentators. In part this was based on the huge rise in injuries in the UK between 1990 and 1995 when numbers soared from 29600 to 58400 [1]

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At the weekend my children were playing on trampolines at a country farm. I will be honest – I have mixed feelings on trampolines. Not a clinical shift goes by with there being at least one child who has had some form of injury from a trampoline (regardless of the presence of ‘safety netting’). And at least on of my colleagues agrees! One the flip side I concede they are great fun.

So how much fun do they have to provide to outweigh the trouble they cause? I was mulling this over while reading a paper on QALY’s recently and decided to have my own stab at health economics.

Lets create a theoretical ‘fun’ index.

The Fun Index

Finding good data to support further calculation is tricky. Surveys have found that 49% of  4-15 year-olds trampoline, while 23% do so regularly [2]. Working out how many trampolines there are in the UK is tricky  – in 2003 40000 were sold but I am having difficulty finding more recent figures [3]. The incidence of trampoline injuries is also difficult to quantify – US data put a figure of 160 per 100000 children in the 5-14 age group [4]. So lets do a back of the napkin calculation:

In an region with 100000 children there will be 49000 who are trampolining. Of these 160 will get injured.

The total amount of fun for those who don’t get injured (and taking a stance that most will have good fun possible) scenario is:

48840 x 0.8 = 39072 units of fun

If all children injured have little fun (again a least possible fun scenario):

160 x 0.2 = 32 units of fun.

Even if children had not much fun on their trampolines you can see the huge numbers of children who don’t get injured will always mean fun will be had!

[note though this approach doesn’t take account of multiple children on a trampoline which clearly increases the fun but also increases in the risk of injury]

I welcome challenge on this approach but only if taken in the spirit of this blog 🙂


[1] AvonSafe – Action for safety report 2011

[2] BBC – The ups and downs of garden trampolines 2012

[3] Bhangal K, Neen D, Dodds R. Incidence of trampoline related paediatric fractures Injury Prevention 2006;12:133–134.

[4] CBS News – Pediatricians warn against trampoline use, citing injury risk 2012

(Some serious but user friendly guides to health economics can be found here and  here)

2 thoughts on “The Fun Index: What level justifies the use of trampolines?”

  1. Hello – I wrote the Avonsafe report you’ve quoted. Avonsafe works to prevent serious childhood injury. I love the ‘Fun Index’! Once, I was accused of trying to stop people having fun, to which I replied “Only if your idea of fun is going to hopsital”

    In my opinion, we cant trade off the pain (and worse) that a minority of children experience against the enjoyment of the majority. This creates a minority who are disadvantaged and says the social injustice is OK, because the majority were not injured. This isnt fair. Should we stop trying to prevent road traffic inuries because they are ‘outweighed’ by the benefits to all the people who are not killed or seriously injured? Course not. Good and bad are not inseparable.

    Another thing is that it is very likely that people would weight (“willingness to accept” economists call it) ‘no fun at all’ (paralysis for the rest of your life, for example) the same as they weight ‘Amazing fun’ for an hour or so. I’d suggest that if ‘Amazing fun’ is scored 1, paralysis should be scored negatively – 39072 perhaps. This means you’d have to ask 39,072 people before you found one willing to accept a lifetime of paralysis in exchange for an hours amazing fun on a trampoline. How should death be scored? Infinately negative?

    We want poeple to be fit and active and to learn and play – where trampolines are concerned I recommend families visit a trampolining club where trained instructors teach skill and control (on olympic sized tramplines).

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