The eGFR is calculated differently based on several factors, including sex and race. So there are different calculation formulas based on male vs female, and African American vs Caucasian. There are not currently differences for other ethnicities, but there are some studies working on validating those.
As you found, HbA1c is glycated Haemoglobin (Hb) the A1c bit refers to the type of Haemoglobin.
POCT is Point of Care Testing. (See https://dx.doi.org/10.1177/1932296814538940
IFCC is International Federation of Clinical Chemistry and Laboratory Medicine (https://www.ifcc.org/) a standardisation program for HbA1c testing
DCCT is the Diabetes Control and ...