Table 1.

Characteristics of included studies

Study	Year	Population size	Patients	NGAL sample	Assay	AKI definition
de Geus et al. [21]	2011	632	General ICU	Plasma and urine	FIA	RIFLE (sCr)
Endre et al. [22,23]	2011	528	General ICU	Urine	ELISA	AKIN or RIFLE (sCr)
Doi et al. [24]	2011	339	General ICU	Urine	ELISA	RIFLE (sCr)
Cruz et al. [25]	2010	301	General ICU	Plasma	FIA	RIFLE (sCr + UO)
Constantin et al. [26]	2010	88	General ICU	Plasma	FIA	RIFLE (sCr)
Mårtensson et al. [27]	2010	25	ICU patients with septic shock	Plasma and urine	RIA	RIFLE and AKIN (sCr + UO)
Metzger et al. [28]	2010	20	General ICU	Urine	ELISA	AKIN (sCr + UO)
Siew et al. [29]	2009	451	General ICU	Urine	ELISA	AKIN (sCr)
Makris et al. [30]	2009	31	ICU patients with multiple trauma	Urine	ELISA	RIFLE (sCr + UO)
Kokkoris et al.a [31]	2011	91	General ICU	Plasma	FIA	RIFLE (sCr + UO)
Linko et al.b	2012	369	General ICU	Plasma	FIA	-

^aStudy published as abstract only; author contacted to obtain extracted data; ^bstudy unpublished. AKI, acute kidney injury; AKIN, Acute Kidney Injury Network; ELISA, enzyme-linked immunosorbent assay; FIA, fluorescence immunoassay; RIA, radioimmunoassay; RIFLE, Risk, Injury, Failure, Loss, and End-stage kidney disease; sCr, serum creatinine; UO, urine output.