Table 2.

Overview of predictive performance of penkid and Screat in patients with low serum creatinine (i.e., SOFA score = 0) at admission

Endpoint	Subgroup	n	Events	Event rate	AUC		Added value of penkid
					Screata	penkida	P value
MAKE	All	579	169	29%	0.831 [0.795, 0.867]	0.838 [0.802, 0.874]	<0.001
	No CKD	500	121	24%	0.815 [0.771, 0.859]	0.818 [0.774, 0.862]	<0.001
	eGFR >75	180	7	4%	0.504b[0.246, 0.722]	0.700 [0.480, 0.905]	0.048
	SOFA = 0	212	13	6%	0.637b[0.459, 0.811]	0.779 [0.639, 0.919]	<0.001
	SOFA = 0/1	336	37	11%	0.704 [0.617, 0.793]	0.749 [0.665, 0.832]	<0.001
AKI	All	582	360	62%	0.948 [0.929, 0.967]	0.854 [0.823, 0.884]	<0.001
	No CKD	502	284	57%	0.936 [0.912, 0.959]	0.826 [0.791, 0.862]	<0.001
	eGFR >75	180	18	10%	0.627 [0.453, 0.800]	0.624b[0.484, 0.762]	0.052
	SOFA = 0	212	30	14%	0.621b[0.483, 0.755]	0.736 [0.634, 0.839]	<0.001
	SOFA = 0/1	337	138	41%	0.898 [0.858, 0.939]	0.761 [0.709, 0.813]	<0.001
WRF	All	576	142	25%	0.734 [0.688, 0.781]	0.778 [0.733, 0.822]	<0.001
	No CKD	497	106	21%	0.714 [0.660, 0.768]	0.755 [0.703, 0.808]	<0.001
	eGFR >75	178	10	6%	0.539b[0.341, 0.752]	0.694 [0.506, 0.880]	0.032
	SOFA = 0	209	16	8%	0.485b[0.286, 0.618]	0.739 [0.608, 0.873]	<0.001
	SOFA = 0/1	334	40	12%	0.649 [0.555, 0.741]	0.715 [0.631, 0.799]	<0.001

AKI, acute kidney injury; AUC, area under the curve; CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; penkid, proenkephalin A 119-159; Screat, serum creatinine; SOFA, Sequential Organ Failure Assessment; WRF, worsening renal function.

^aAUC with 95% confidence intervals.

^bP > 0.05; all other univariate P < 0.05.