Table 1.

Critical appraisal of selected studies

Study	Critical appraisal items
	Relevance		Validity
	Domain	Determinant	Randomization		Blinding	Standardization	Missing data		Follow-up
			Allocation	Similarity			%	Reason	%	Reason	ITT analysis
Bauer 2000 [11]	+	+	+	+	+	+	-	-	−	+	+
Cahill 2011 [12]	+	+	x	x	−	−	-	-	-	-	−
Casaer 2011 [13]	+	+	+	+	+/−	+	-	-	-	-	+
Doig 2013 [14]	+	+	+	+	+/−	+	+	+	+	−	+
Heidegger 2013 [15]	+	+	+	+	+/−	+	-	-	+/−	+/−	+
Kutsogiannis 2011 [16]	+	+	x	x	−	−	-	-	-	-	−

Specification per item: Domain: critically ill adult patients on the ICU? + = yes, − = no. Determinant: parenteral nutrition? + = with PN, − = no PN. Randomization: concealed treatment allocation? + = yes, − = no; similarity subgroups in baseline characteristics? + = yes, − = no. Blinding: + = yes, +/− = partial, − = no. Standardization: + = yes, − = no. Missing data: percentage? + = <5%, +/− = 10%, − = >10%; reason? + = reason given, − = reason not given. Follow-up: percentage? + = <5%, +/− = 10%, − = >10%; reason? + = reason given, +/− = not all reasons given, − = reason not given; ITT analysis? + = yes, − = no. ITT analysis, intention to treat analysis; x, not applicable.