Risk Factors for Development of Acute Kidney Injury in Critically Ill Patients: A Systematic Review and Meta-Analysis of Observational Studies

Table 2

Quality of the studies utilizing the Newcastle-Ottawa quality assessment scale (maximum score of 9).

Cohort studies
	Selection				Comparability	Outcome			Total score
First author, year	Representativeness of exposed cohort	Selection of the nonexposed cohort	Ascertainment of exposure	Demonstration that outcome was not present at start of study	Comparability; on the basis of design or analysis	Assessment of outcome	Followup long enough	Adequacy of followup of cohorts
Hilberman; 1979 [43]	*		*			*	*		4
Wilkins 1983 [53]	*	*	*			*	*	*	6
Groeneveld 1991 [42]	*	*	*		*	*	*	*	7
Tran 1994 [51]	*	*	*			*	*	*	6
Zanardo 1994 [54]	*	*	*	*	*	*	*	*	8
Ward 1996 [52]			*		*	*			3
Vivino 1998 [5]	*	*	*	*	*	*	*	*	8
Mangano 1998 [48]	*	*	*	*	*	*	*	*	8
Conlon 1999 [36]	*	*			*	*	*	*	6
De Mendonça 2000 [4]	*	*	*		*	*	*	*	7
Clermont 2002 [35]	*	*	*			*	*	*	6
Bove 2004 [33]	*	*	*	*	*	*	*	*	8
Bahar 2005 [30]	*	*			*	*	*	*	6
Chawla 2005 [34]			*	*	*	*	*	*	6
Loef 2005 [46]	*	*	*			*	*	*	6
Mataloun 2006 [49]	*	*		*	*	*	*	*	7
Hoste 2006 [6]	*	*	*		*	*	*	*	7
Landoni 2007 [45]	*	*	*		*	*	*	*	7
Barrantes 2008 [31]	*	*		*		*	*	*	6
Bagshaw 2008 [28]	*	*	*			*		*	5
Bagshaw et al., 2008 [29]	*	*	*			*		*	5
Abelha 2009 [27]			*		*	*		*	4
De Araújo Brito 2009 [39]			*		*	*		*	4
Thakar 2009 [50]		*				*	*	*	4
Hobson 2009 [44]	*	*	*	*		*	*	*	7
Machado 2009 [47]		*				*	*	*	4
Gomes 2010 [41]	*	*	*			*	*	*	6
Case-control studies
	Selection				Comparability	Exposure			Total score
First author, year	Case definition adequate	Representiveness; of cases	Selection of controls	Definition of controls	Comparability; on the basis of designs or analysis	Ascertainment of exposure	Same ascertainment method	Nonresponse rate
Corwin 1989 [37]	*	*			*				3
Boucher 1990 [32]	*	*		*	**	*	*	*	8
Ficher 2002 [40]	*				*	*	*		4
Dasta 2008 [38]	*	*			*	*	*	*	6