FEV1 calculations

NYCLawGirl

New member
Hey everyone,

Just wondering if anyone knows whether there is a "gold standard" for predicted FEV1 calculation. I did some internet searching (always 100% reliable when it comes to medical stuff <img src="i/expressions/face-icon-small-wink.gif" border="0">) and found about 5,000 different equations, many of which were pretty different and led to a large variation in percent predicted. Of course this makes me question the accuracy of that number at all if it's going to vary so much depending on the preferred equation -- scary when you consider how much we rely on our percent FEV1 for things like transplant!

Anyway, do you guys know if there is one particular method that is commonly used in CF centers? I have a home meter and would really like to be able to accurately convert to a percent here at home, but I don't actually keep print outs of my PFTs (bad, I know).

Thanks.
 

NYCLawGirl

New member
Hey everyone,

Just wondering if anyone knows whether there is a "gold standard" for predicted FEV1 calculation. I did some internet searching (always 100% reliable when it comes to medical stuff <img src="i/expressions/face-icon-small-wink.gif" border="0">) and found about 5,000 different equations, many of which were pretty different and led to a large variation in percent predicted. Of course this makes me question the accuracy of that number at all if it's going to vary so much depending on the preferred equation -- scary when you consider how much we rely on our percent FEV1 for things like transplant!

Anyway, do you guys know if there is one particular method that is commonly used in CF centers? I have a home meter and would really like to be able to accurately convert to a percent here at home, but I don't actually keep print outs of my PFTs (bad, I know).

Thanks.
 

NYCLawGirl

New member
Hey everyone,
<br />
<br />Just wondering if anyone knows whether there is a "gold standard" for predicted FEV1 calculation. I did some internet searching (always 100% reliable when it comes to medical stuff <img src="i/expressions/face-icon-small-wink.gif" border="0">) and found about 5,000 different equations, many of which were pretty different and led to a large variation in percent predicted. Of course this makes me question the accuracy of that number at all if it's going to vary so much depending on the preferred equation -- scary when you consider how much we rely on our percent FEV1 for things like transplant!
<br />
<br />Anyway, do you guys know if there is one particular method that is commonly used in CF centers? I have a home meter and would really like to be able to accurately convert to a percent here at home, but I don't actually keep print outs of my PFTs (bad, I know).
<br />
<br />Thanks.
 

Lex

New member
Hey Piper...
When I was evaluated at Columbia, they warned me that their number * might * be different from Yale. They informed me that they used a slightly different calculation. To be quite honest, I didn't care about the actual difference at the time. However, my FEV1 was actually the same.

I think using different methods will discredit validity, but as long as the same method from our regular place of testing is reliable, that's the best we can hope for <img src="i/expressions/face-icon-small-smile.gif" border="0">
 

Lex

New member
Hey Piper...
When I was evaluated at Columbia, they warned me that their number * might * be different from Yale. They informed me that they used a slightly different calculation. To be quite honest, I didn't care about the actual difference at the time. However, my FEV1 was actually the same.

I think using different methods will discredit validity, but as long as the same method from our regular place of testing is reliable, that's the best we can hope for <img src="i/expressions/face-icon-small-smile.gif" border="0">
 

Lex

New member
Hey Piper...
<br />When I was evaluated at Columbia, they warned me that their number * might * be different from Yale. They informed me that they used a slightly different calculation. To be quite honest, I didn't care about the actual difference at the time. However, my FEV1 was actually the same.
<br />
<br />I think using different methods will discredit validity, but as long as the same method from our regular place of testing is reliable, that's the best we can hope for <img src="i/expressions/face-icon-small-smile.gif" border="0">
 

LouLou

New member
My center uses Collins but I know HUP/CHOP uses a different equation. I have started to just look at my raw score...why not find out what your scores are from the past year or so and use those as a basis for home evaluation? Seems a lot simpler unless the home meter has a programming option where you can pick the equation from a drop down list or something. If that is the case I would just find out what the name of the equation that ColPres uses and plug it in. Did you get insurance to cover the home meter? Was it recommended by your doctor or just another cf "toy" you wanted in your arsenal?
 

LouLou

New member
My center uses Collins but I know HUP/CHOP uses a different equation. I have started to just look at my raw score...why not find out what your scores are from the past year or so and use those as a basis for home evaluation? Seems a lot simpler unless the home meter has a programming option where you can pick the equation from a drop down list or something. If that is the case I would just find out what the name of the equation that ColPres uses and plug it in. Did you get insurance to cover the home meter? Was it recommended by your doctor or just another cf "toy" you wanted in your arsenal?
 

LouLou

New member
My center uses Collins but I know HUP/CHOP uses a different equation. I have started to just look at my raw score...why not find out what your scores are from the past year or so and use those as a basis for home evaluation? Seems a lot simpler unless the home meter has a programming option where you can pick the equation from a drop down list or something. If that is the case I would just find out what the name of the equation that ColPres uses and plug it in. Did you get insurance to cover the home meter? Was it recommended by your doctor or just another cf "toy" you wanted in your arsenal?
 

Landy

New member
I have heard the CFF recommends the Hankinson reference. I happen to like Morris/Polgar reference, because it calculates to a higher FEV%! <img src="i/expressions/face-icon-small-wink.gif" border="0">

Of course you know that the FEV1 liter number will always be the same, no matter what reference you use. Because of this, I try to see how my FEV1 in liters changes.

Hope this wasn't too confusing<img src="i/expressions/face-icon-small-confused.gif" border="0">
 

Landy

New member
I have heard the CFF recommends the Hankinson reference. I happen to like Morris/Polgar reference, because it calculates to a higher FEV%! <img src="i/expressions/face-icon-small-wink.gif" border="0">

Of course you know that the FEV1 liter number will always be the same, no matter what reference you use. Because of this, I try to see how my FEV1 in liters changes.

Hope this wasn't too confusing<img src="i/expressions/face-icon-small-confused.gif" border="0">
 

Landy

New member
I have heard the CFF recommends the Hankinson reference. I happen to like Morris/Polgar reference, because it calculates to a higher FEV%! <img src="i/expressions/face-icon-small-wink.gif" border="0">
<br />
<br />Of course you know that the FEV1 liter number will always be the same, no matter what reference you use. Because of this, I try to see how my FEV1 in liters changes.
<br />
<br />Hope this wasn't too confusing<img src="i/expressions/face-icon-small-confused.gif" border="0">
 

Jennyvb17

New member
I've always wondered why we didnt have a way to measure at home. Had no idea you could get something for 50 to 60 bucks.
Might have to put it on my birthday list, it would be nice to know some days
 

Jennyvb17

New member
I've always wondered why we didnt have a way to measure at home. Had no idea you could get something for 50 to 60 bucks.
Might have to put it on my birthday list, it would be nice to know some days
 

Jennyvb17

New member
I've always wondered why we didnt have a way to measure at home. Had no idea you could get something for 50 to 60 bucks.
<br />Might have to put it on my birthday list, it would be nice to know some days
 

jbrandonAW

New member
My doc told me that the only thing that is different from clinic to clinic id the percent number. The actual liters number will be the same. I was pretty shocked when I learned this, so I have spent more time focusing on my actual liters number than my %.
 

jbrandonAW

New member
My doc told me that the only thing that is different from clinic to clinic id the percent number. The actual liters number will be the same. I was pretty shocked when I learned this, so I have spent more time focusing on my actual liters number than my %.
 

jbrandonAW

New member
My doc told me that the only thing that is different from clinic to clinic id the percent number. The actual liters number will be the same. I was pretty shocked when I learned this, so I have spent more time focusing on my actual liters number than my %.
 

Asexyblond23

New member
My clinic does the NHanes III, not sure what it is but thats the type they always use. It is different then the clinic in louisville that I was at.
 

Asexyblond23

New member
My clinic does the NHanes III, not sure what it is but thats the type they always use. It is different then the clinic in louisville that I was at.
 
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