Anderson S, Halter JB, Hazzard WR, Himmelfarb J, Horne FM, Kaysen GA, Kusek JW, Nayfield SG, Schmader K, Tian Y, Ashworth JR, Clayton CP, Parker RP, Tarver ED, Woolard NF, High KP. Prediction, progression, and outcomes of chronic kidney disease in older adults. J Am Soc Nephrol. 2009 Jun; 20(6):1199-209.