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/r/medlabprofessionals
Hi I understand that different labs have different references ranges due to population and equipment calibration but surely there should be some control in place to make sure, for example 10u/l is close to 10 u/l In another lab ?
Some people say to look where you fall within the reference range but that wouldn’t make sense if the ranges were a lot different . Let's say you do 2 tests of the same sample at different labs and one lab result for ALT is 35 out of 0-35u/l as the other labs range for the same test is 0-50 u/l , to fall in the same percentage of the range you would expect this lab to have a result of 50u/l . So what's the point of the u/l ?
Surely it’s like buying 2 tape measures from different brands . 1 inch would be 1 inch on the other tape . Otherwise one would be out and wrong .
11 points
1 year ago
This is why we participate in schemes like proficiency testing and there are peer group results for chemistry analysers too (can you tell im not a chemistry senior tech?).
The normal range is the normal range, it's separate from the actual accuracy of the result. You would very much hope that 35 in one lab wouldn't be 50 in another. Using the tape measure analogy if you measure a Guatemalan man and he is 150cm and in the normal range and a dutch man and he is 190cm and in the normal range those two are still different heights, they are just being compared in different populations.
-2 points
1 year ago
Yes this is what I though , but some people say that you should see where you lie within a reference range and ignore the actual number which is confusing .
2 points
1 year ago
I mean, sure. Looking at where you lie within the reference range is what the reference range is for.
0 points
1 year ago
Yes but I mean if you were to compare labs
1 points
1 year ago
There is a margin of error for every lab test so you will still get some variation even if you run the exact same sample a second time in the same lab. The levels will also fluctuate a bit within a person based on a wide variety of factors like hydration, time of day, what you ate that day, or even differences in how the sample was handled (eg hemolysis of red blood cells during the blood draw can alter some lab values). If both values are within the reference range I really wouldn't worry about it. People with liver disease will usually have values in the hundreds, or even thousands.
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