I've read quite often that eGFR between 60-90 are wildly inaccurate. In fact one article I read in JAMA says eGFR's over 60 are of no diagnostic value what so ever and should not be further calculated or even recorded. And repeat testing is not recommended. And in most individuals who fall in this range the eGFR is greatly underestimated. By as much as 40% or more. One example they gave was a tall man, 6'2 260 lbs with an eGFR of 64. Upon further evaluation they determined the mans eGFR was actually around 90. The article goes on to say that eGFR's under 60 and over 90 are much more reliable.
My question is why is this? There much documentation out there that talks about eGFR especially right around 60 are likely to be completely inaccurate and should not be used at all to diagnose kidney disease. But I have yet to read anything on why this occurs. Any thoughts?
37 year old husband has eGFR of 75-worried about future
eGFR 39/40 but GP doesn't seem concerned.
Same Lab, Same Creatinine levels - Different Egfr's
At what eGFR did the dr tell you there was a problem? 
