Piano Tuners and Pre-op assessment

Posted By Paul Cooper |  last update 10-Mar 2011

"how many piano tuners are there in Chicago". No other information given.

I was first posed this problem at school in the 1970s , and expected to come up with an answer. (125, as you ask)

Its an example of a Fermi problem. Make some reasonable assumptions, and see what you get. if you make  enough assumptions and there is no systematic bias then you should get a 'reasonable' answer and the overassumptions and under-assumptions should cancel each other  out .

So

q how many pre-assessment nurses are there in the UK ?

1. There are 3 million procedures performed /yr  in the UK, and the vast majority  will have a preoperative assement  of some sort.
All the pre-op assessment clinics i know of are staffed by nurses .

So 3 million procedures = 3 million assessments by nurses

2. An appointment  + associated paperwork will on average  be 40 mins.
So in a working day a nurse will see  9 patients   ( = 6 hours + hour for lunch + hour for other sundry tasks).
In a working week this is 9 x 5 = 45 patients.

3. A nurse will work for 45 weeks /yr , so in a year 1 nurse will see 45 x 45 patients = approx 2000 pts

so 3 Million / 2000 = 1500  nurses nationally .

And there are 168 Acute Trusts in the UK ( as of 2009) http://en.wikipedia.org/wiki/NHS_hospital_trust

so this means  1500 / 168 = 8.9 nurses / Trust

To check this Ive just rung up our preop assessment unit for my medium-sized Trust and asked how many WTE nurses we have.

We have 6.

Who needs expensive, time -consuming national surveys then ?