The standard way to check for kidney problems is to have a blood test and the test centre assesses your kidney function by calculating your glomerular filtration rate using various factors including the serum creatine level measured. There is a standard equation into which is fed your age, sex, race and creatine level to calculate the filtration rate. The equation was proposed in 1999 and is known as the MDRD equation.
Recently researchers at the Johns Hopkins Hospital compared results from this equation with a new method, the CKD-EPI equation, looking at patients who were known to have kidney problems. The study looked at data from over one million patients! The results from using the new calculation method were found to be better at predicting whether patients had kidney problems, often putting patients into a higher category of risk than the older method.
The study involved over 200 collaborators and data from 40 countries. The original research was published in May 2009, and slowly labs are beginning to swap to using this newer way to calculate patient risk, a methodology that took almost ten years of research to come up with.