Carefully look at your lab test results-... - Early CKD Support

Early CKD Support

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Carefully look at your lab test results-all depends on the normal range for each lab.


Just in case others may experience what I just did I will give my most recent experience: (when we compare our test result numbers on here remember they may all be wildly different numbers but mean the same thing)":

Due to my stage 3 egfr (caused by only one kidney) and renal metastatic cancer, I get all sorts of testing. some every 3 weeks (blood), some as required (scans, etc.) and some every 3 months (urine).

I generally go to one of our local hospitals for my tests. Lets call it Hospital "A". They post the results online so I can see them immediately, long before my doctors appointments. Recently another hospital nearer to me, call it Hospital "B" also started to post tests online for immediate review. So I went to them for a urine test.

Everything came out normal or negative (good result). I pay particularly close attention to my Urine Mirco-albumin level (protein). It was "less than 6 mg/dl" classified as normal. But in my mind this seemed higher than what I'm used to reading. So I looked at my last few tests at hospital "a" (that I've normally used). There all my tests report "less than .5 mg/dl". Naturally worry overcame me. What?? My level jumped from <.5 up to 6! not .6, but 6!! Both reported as mg/dl.

Then after repeated inspection of the results I noticed something. The normal range for the hospital report 6mg/dl, was set at less than 30mg/dl. So to them anything less than 30mg/dl is normal. And they measured 6. BUT the old hospital considers the normal range anything less than 3mg/dl as normal so my .5 value is normal.

So while they both reported my result as mg/dl their scale of normal for one lab was less 3.0 mg/dl and the other was less than 30 mg/dl.

SO, when we on here report to each other our test results we must consider the lab that produces the results have DIFFERENT normal ranges. Look at my example. If I wrote to you my result was .5 and another time it was 6.0, it would look like some dramatic change. But actually based upon the "normal" range for each lab, they are basically the same!!!

7 Replies

I have recently had an issue between 2 hospital results:Hospital A: eGFR over last 3 years varying between 33-38

Hospital B:eGFR dropping from 56-43 in 12 months.

So hospital B now thinking there’s a big decline (I’m 42 y/o) but Hospital A have been relatively stable, but generally at a much lower eGFR!

And Ferritin results at Hosp B was low at 8 and consultant wants me to have iron infusion, and Hosp A Ferritin is 18, within range, no need for iron infusion! Aaaggghhh!!!

RickHow in reply to madonbrew

Wow. And I thought my difference between hospitals was crazy. For your egfr it might be that they are using 2 different formulas. There are different ways to calculate egfr. Which of course leads to problems like you are having. I had a similar experience about egfr. I had it tested one afternoon at my oncologist. Had my kidney removed in 2017. Since then I have never been above 44. Usually in the upper 30's. The result this time came out 53!!! The very next morning my regular GP did a test. It came out 38!! Now egfr can fluctuate, but come on.

madonbrew in reply to RickHow

That feels really similar to mine! It’s a bit odd isn’t it, even considering the different formulas and factors.

As there are several formulae used around the world to work out the GFR results, it very much depends on which one each test facility uses. Find a formula then figure out your own results consistently, to get a comparable results for yourself. I use an Australian one that is flatteringly higher than most, but it is the one my test facility uses. Consistency matters more than the figure, not that the figure doesn't matter at all. With CKD age, ethnicity and gender all have an effect. Then of course there is human error. As the GFR can fluctuate hourly depending on what you have done or consumed and when. I try to keep to the same time of day to have my tests done and hold off when I have broken my diet or been physically active prior to testing.

RickHow in reply to Cheyne13

Well said.

I don't know why, to me, it should all be standardized, but all facilities may use different ranges for what is normal. I think it has something to do with whatever testing or additives they use. Good post/

Good point!

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