Overall , the risk of hospitalization for heart failure among the three eGFR groups of patients was 2.2 % ( referent ) , 7.4 % ( adjusted hazard ratio [ HR ] 2.38 [ 95 % CI 1.95-2 .91 ] , P < 0.001 ) , and 13.0 % ( adjusted HR 4.59 [ 95 % CI 3.28-6 .28 ] , P < 0.001 ) , respectively .