I had asked whether you recognized eGFR as the lab result and have not heard back.
The eGFR, or estimated glomerular filtration rate, is a reflection of kidney function. The GFR is a very accurate measure of kidney function, but requires collection of urine for 24 hours for an accurate determination. The eGFR is a method for estimation of the GFR that can be done more easily, using the patient's age gender, and creatinine level.
An eGFR that is below 60 is considered an indication of kidney disease, and the lower the number, the worse the kidney function.
The disadvantage of the eGFR is that it is dependent on the creatinine, and there are conditions that can affect the creatinine besides kidney disease. For example, any condition that can cause dehydration will cause an increase in creatinine, even when the kidneys are unchanged, so the eGFR will decrease despite normal kidney function. So, if the eGFR is low, it may require a consultation with a Nephrologist, but it also should prompt consideration of whether there is any other condition that can affect creatinine levels.
If I can provide any additional information, please let me know.