At 1-year follow-up , the mean change in eGFR for the overall cohort was -1.0 15.1 mL/min/1 .73 m ( 2 ) ; for patients with CKD stage 1 or 2 , stage 3 , or stage 4 or 5 , mean change was -4.1 16.6 , +2.6 12.4 , and +4.8 9.5 mL/min/1 .73 m ( 2 ) , respectively .