This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
The version of Liver enzymes drifting that circulates here is a simplification of a simplification. It is not wrong, but it has lost the conditions under which it holds, and those conditions are where the interesting cases live.
Two people in this thread mean different things by Liver enzymes drifting and are disagreeing about the definition while believing they are disagreeing about the facts. Worth pausing to define it.
Reading back through, this was answered upthread and I missed it. My fault.
Marking my uncertainty on Liver enzymes drifting explicitly. I am confident about the direction, much less confident about the size, and not confident at all that it generalises past the case in the first post.
On post #34 — agreed on the reasoning, with one qualification.
Repeat before acting is standard practice for an isolated abnormal result on most analytes, and it is standard for a reason.
Where I would look next, rather than where I would stop.
Where I part company with post #37, and it is a narrow parting.
Liver enzyme changes during rapid weight loss are commonly reported and have several possible explanations, which is exactly why they need clinical interpretation rather than forum interpretation.
Post #37 is the version of this I will quote in future. One addition.
A trend needs at least three points to be a trend. Two points are a line and a line through noise is still a line.
That is clearer than the version I had in my head. Thank you.
Post #40 and I disagree about the size of the effect, not about the direction.
Sample handling before analysis affects several analytes, and a haemolysed sample produces predictable artefacts that a laboratory will usually comment on.
Reference intervals: constructed to contain the central 95% of a reference population, which means one in twenty healthy people falls outside one by definition. Add biological variation and analytical imprecision and the base rate of a meaningless flag is substantial.
Reporting the observation and leaving the explanation open deliberately.
Everything in post #44 holds. The case it does not cover is the one I have.
On Liver enzymes drifting, the part that usually goes wrong is that the question is asked as though it has one answer. It has a range, and the width of the range is the interesting bit.
If you can post the two or three numbers you are working from, several people here will check the arithmetic rather than argue about the conclusion.
I changed my mind about Liver enzymes drifting after someone here asked me for the source and I could not produce one. That is worth saying out loud because it is the ordinary way it happens.
Confirming post #46 from a second method, which matters more than confirming it from a second person.
Liver enzymes drifting sits at the boundary between what this community can usefully discuss and what it cannot, and I think it falls on the discussable side, narrowly.
A single value outside interval: usually uninformative on a single draw. What makes a result interesting: a trend across multiple draws, a magnitude well beyond the interval, a pattern that coheres with other values, or symptoms that fit.
Filing a mild objection to the consensus on Liver enzymes drifting. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit.
Analytical imprecision: any measurement has an error margin. A small difference in consecutive tests is usually measurement noise, not a real change. Knowing the imprecision helps distinguish noise from signal.
Same conclusion as the reply above, reached differently, which is mildly reassuring.
This follows post #51 rather than contradicting it.
Liver enzymes: elevation does not specify cause. ALT and AST can rise from many things. Bilirubin helps narrow down the cause. Multiple markers together are more informative than one alone.
That is what I would do. It may not be what is correct.
Reading this Liver enzymes drifting thread as someone who came in with a fixed view: the third and seventh replies moved me and the confident ones did not.
The number people quote for Liver enzymes drifting is a central estimate presented without its interval, and the interval is wide enough that the estimate is nearly uninformative on its own.
A trend needs at least three points to be a trend. Two points are a line and a line through noise is still a line.
That has been true for the cases I have seen and I have not seen many.
Confirming post #59 from a second method, which matters more than confirming it from a second person.
Reference intervals: constructed to contain the central 95% of a reference population, which means one in twenty healthy people falls outside one by definition. Add biological variation and analytical imprecision and the base rate of a meaningless flag is substantial.