The glomerular filtration rate was measured or estimated in the included studies using a range of methods, including using the Modification of Diet in Renal Disease Study equation,35,40,55,67,78,80,82,85 Chronic Kidney Disease Epidemiology Collaboration equation,15,16,18, 19, 20, 21, 22, 23,27,46,54,64,66 Cockroft and Gault formula,62 creatinine clearance,25,31,34,52,53,56,63,64,68,71 and clearance of 125I-iothalamate24,60 or cystatin.78 This evidence concerns the gene CST4 and chronic kidney disease.