Eight hundred fifty-four patients with baseline mean eGFR 61.5 23.1 mL/min/1 .73 m ( 2 ) were studied , including 438 ( 51.3 % ) with eGFR 60 mL/min/1 .73 m ( 2 ) ( CKD stage 1 or 2 ) , 371 ( 42.6 % ) with eGFR 30 to 59 mL/min/1 .73 m ( 2 ) ( CKD stage 3 ) , and 52 ( 6.1 % ) with eGFR < 30 mL/min/1 .73 m ( 2 ) ( CKD stage 4 or 5 ) .