Quest Free T Reference Ranges

[econnolly]

Hello,

I had blood work done in May and the reference range for Free T was- 35.0-155.0 pg/mL

Just had them done again in October and they changed to - 46.0-224.0 pg/mL

Anyone know why they changed this seems like a big jump?

 

[Gman86]

Hello,

I had blood work done in May and the reference range for Free T was- 35.0-155.0 pg/mL

Just had them done again in October and they changed to - 46.0-224.0 pg/mL

Anyone know why they changed this seems like a big jump?

Been getting labs done at quest for around 5-6 years now. They didn’t change it. You just had two different tests done. If you can, check the test codes, I bet they’re different from May and October.

I usually always get their total test, free test + bio available lab done. It also includes SHBG and albumin. This last time the lady ran the wrong one and it only tested total test and free test. The reference range for this lab has the (35.0-155.0). The lab that I usually get done has the reference range (46.0-224.0). Been this way for years

 

[econnolly]

Where would I see the test code? Also, why would the reference range be different but the results be tested on a similar range, wouldn't this make doing one test seem way out of range vs another?

 

[Gman86]

I usually have them print me out a copy of the labs I’m having down after the person is done putting it into the computer right before they draw my labs. Not sure where to find it after the fact. Was this just their free T test, or was it their total and free T test?

I’ve only had labs done twice where they used the lower reference range. I just always use the higher reference range one. I wonder if the way they test the free T is different depending on which reference range they use

 

[Vince Carter]

He's right, there is more than one test for most all of the tests that they input and is entirely dependent on what the tech selects and inputs. Right too that Quest will hand a paper sheet to verify personal info but if you look at the bottom there is a list of the tests that they input. Call it out if its wrong. Though be aware they input what the Dr writes/etc and they won't interpret or do any thing else based on what you think, or know, is wrong.
If you mean to have the "Sensitive Estradiol" and the Dr writes "Estradiol", they won't change it.

 

[econnolly]

So regardless of the reference range the actual numbers would be the same correct? For example if I am comparing my results from May to Oct. side by side to see any changes would this make sense?

 

[Cataceous]

So regardless of the reference range the actual numbers would be the same correct? For example if I am comparing my results from May to Oct. side by side to see any changes would this make sense?

No, the numbers are not particularly comparable. You might consider the percent of the reference range, and compare those values. But free testosterone measurements can be problematic in general, so I wouldn't rely on these. Your October value is probably calculated by the Vermeulen method, which has been useful, but is supplanted by the newer Tru-T method. I think overall it's preferable to measure total testosterone and SHBG, then use the Tru-T calculator. Total testosterone and SHBG tests tend to be more consistent, though it's still best to use the same lab and test types.