Design and methodology of the Aging Nephropathy Study (AGNES): a prospective cohort study of elderly patients with chronic kidney disease - Coelho, Venceslau A; Santos, Giovani GN; Avesani, Carla Maria; Bezerra, Cicero Italo L; Silva, Luana Cristina A; Lauar, Julia C; Lindholm, Bengt; Stenvinkel, Peter; Jacob Filho, Wilson; Noronha, Irene de Lourdes; Zatz, Roberto (Bmc nephrology, 2020)