PFT's - percentages vs. raw data numbers

[LouLou]

Any of your doctors encouraging you to focus on the number not the percentage?

Mine is for a few reasons he says:

1. Everytime you use a new machine the different systems have different expected yields (in my case this is important because I've moved every 4 years of my life and this trend doesn't seem to be stopping)

2. Your percent expected goes down each year - I guess they expect you to loose a certain % each year even if you don't have CF. So it's possible that you could have declined in volume but the % would be up.

He wants me to look at my numbers.

It's so much more fun to compare % though because we'll all have different volumes based on sex and height.

Anyway in case this means anything to anyone I'm shooting for an over 2.0 for my FEV1 and and over 3.0 on my FVC.

If you've been at the same clinic for a while and you're staying put then the percentage is a good basis for comparison just keep in mind #2 mentioned above.

 

[Emily65Roses]

My doc and I really base how I'm doing on how I feel and what new limits I do or don't have, more than anything. It's the same idea, though. Not to put SO MUCH importance on PFT #s. We still do PFTs and count them, of course, but he pays attention to what I say at least as much as what the papers say.

<b>Edited to add:</b> It seems I didn't quite understand you right. It's late and my brain is already asleep. Sorry for that. <img src="i/expressions/face-icon-small-smile.gif" border="0">

 

[thelizardqueen]

My doctor says the very same points that you just posted. That every machine is different, that its pretty much enevitable for #s to go down per year. If we're talking #s though - my percentages are: FEV1 - 69%, FEVC - 72%. My #s are: FEV1 - 2.50, and FEVC - 3.01. But again I'm down from 2004 which was FEV1 - 2.68, and FEVC - 3.08. Its a bummer yes, but I suppose just a # that I need to improve on.

 

[Allie]

I like pecentages, maybe because it's easier for me to understand from person to person? Maybe I'm stupid lol.

 

[lovingBenandCambree]

I like % too, its just easier for me to remember. However, there was a big change when I went from Primary Childrens to the you for that very reason.

Emilee

 

[luke]

Lauren,

I think that it is good to keep track of both....however your PFT's predictive values changing from machine to machine doesn't make sense because they almost all use the same ones, Knudson 1983, if I remember correctly. Not to mention if the machine is not set that way the RT can always change it per the doctor's order in a second. I do believe the predicteds are important though because as your stats change your predicteds changes, certainly a 60 yr old woman PFT's won't be the same as when she was 25 simply because she older. So even though her true number is less....it still may be considered "normal" for her age. Anyway....just so 6am rambeling so I can put off the gym for another 3 minutes.

luke

 

[Scarlett81]

I like % too. And I use the same machine everytime I go for a checckup anyway.
My doc puts alot of weight on PFTs but also how I feel, how I look-if I look very tired, pasty and pale-she knows somethings up. I think she can tell if I go in the office and I was too tired to put on makeup or brush my hair-I must not feel well. I would say she pulls a little bit from everywhere to asess me.