peak flow charts/calculations - Asthma Community ...

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peak flow charts/calculations

I been looking around and page 49 of this give widely different predicted peak flows to anything I've seen before. How accurate is this or come to that other predictions?

15 Replies

Looks OK to me!

It predicts what mine should be 475 which I have know for a few years.

I have always been aware of this type of charting of peak flows both pre and post EU scales.

I would assume that as it is an AUK Document then it will be pretty good.

There are always going to be variables and anomalies in people.


is just over 6% higher than what I'd previously been told for me.

When they changed to EU guidelines, the lower the original reading was, the lower it translated

eg 200 became 160

And the higher end it increased, so say, 680 became 720

There is a happy medium somewhere where the middle ones are similar, old and new.. See if there are any old scale to EU conversion charts still around - I think Clement Clarke had one on their site a couple of years ago.

Don't get too hung up about little differences.

I was a tad anoyed cos all my prediced ones went down!

eg 220 became 185!!! Oh and they are my predicted best and have been that for years being a brittle/ severe asthmatic.

I've always been told it's best to use your personal best values if these are known and recorded, particularly, if as in my case, personal best is quite a bit higher than predicted as this has implications for drops causing concern - it's why drops are done on percentages not absolute numbers.

I've not seen a full list like that before - so my PEF is currently that predicted for an 80 year old of my height (I'm 30) :(

I'm going to take up shrinking, that way people will expect less of me.

I'm amazed at how much lower the values are for women - do women have smaller lungs?

Yeh, i'm not bothered really, my best is more than the chart predicts, but the clement clark figure is what i'd used, and this chart puts that as if i'm 20 years older. Just trying to establish if it was accurate and how medical staff get on if the used that leaflet, or maybe we get told a lower level so we shut up. LOL

Ratty, actually womens lungs are smaller in volume, but also reduced muscle would make the force of expulsion lower. not guaranteed as a lazy cough potato male would have a lower value than an athletic female.

It predicts 460 for me - my personal best is 500 but I have been told previously that mine is above average a little, possibly due to the amount of swimming I have done since my very early teens.

Not sure really woody, it looks not dissimilar for me to what I've seen before.


Just had a look at the clement clarke which predicts 439 for me as opposed to 460 on the AUK document, so not hugely different.

Most health professionals I've spoken to ask me about my PB and go off that for assessing my asthma.

Sorry for multiple posts but I just found a really good site with old and new PF meters.

Hope you can access it - give it a go.


fee, thats nearly 6% agian.

the predictions for me was 645, but the chart in the doc was 686 (6% above previous figure), but my best is 768, and the doc said 800 would not be unexpected considering my background.

I think the clement clarke one on the site is more accurate, based on everything i've read, but was surprised as this was the first time i'd seen the AUK publication and noticed the difference.

Chart would suggest I'm aiming for 420 when my personal pest is nowhere near. Going to go give this a bye and only worry if practice nurse says so.

Just noiiced I typed 'pest' instead of 'best'. LOL Mind you, sometimes asthma can be a pest.

GM, this one seems to be the most accurate, the majority produce results in line with this.

Hi woody,

In which case I'm running at half strength. Which is why on this singulair - hope its worth the effort.

Hi GM,

Really do hope the effort pays off, but don't worry, the figure is a prediction, but females can have a level upto 80ltrs lower and still be considered as normal, so aim for the lower normal limit to start with, and I know how you feel, until i got things under control I was less than 50% of predicted, so you have hope. hope you had a good sleep

I think Ratty mentioned this below, but AUK's policy on Kick Asthma holidays is based on the child's personal best peak flow reading rather than an estimate from a chart. If their peak flow drops a certain percentage below their PB we have action plans to follow to deal with the situation.

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