Excluded studies
Following screening, we identified 17 studies as potentially relevant (see Figure 1). Upon closer review we excluded all but one of the studies (as well as one ongoing study), for the following reasons: different routes of delivering enteral nutrition compared (gastric versus small bowel feeding (Meert 2004); continuous versus intermittent gastric feeding (Horn 2003); immune-enhancing formula versus standard formula (Alberda 2005; Albers 2005; Barbosa 1999; Briassoulis 2005; Briassoulis 2005b; Briassoulis 2006; Gottschlich 1990; Marin 2006; Papadopoulou 2000); two regimens of early combined enteral and parenteral nutrition compared (Alexander 1980); only surrogate nutritionalmarkers as outcomes (Chaloupecky 1994); study population was primarily adult (Hadley 1986;Hausmann 1985; JustoMeirelles 2011; Kolacinski 1993; Peng 2001; Suchner 1996; Young 1987); study population was premature neonates or newborn infants in the neonatal intensive
care unit (Black 1981; Morgan 2013); and study population was not critically ill children (that is, children not cared for in
a PICU) (Khorasani 2010; Marín 1999; Pillo-Blocka 2004). See ’Characteristics of excluded studies