- Estimated GFR (eGFR) based on serum creatinine between 40 and 99.9 ml/min/1.73 m2 at screening. The upper and the lower limits should be decreased by 1 ml/min/1.73 m2 for each year over age 60 (with a lower limit of 35 ml/min/1.73m2) and by 10 ml/min/1.73 m2 for strict vegans.