Table 1.

Results of quality assessment of studies on NEC related prognostic factors according to the QUIPS tool [17]

Study	Study participation (max. 15)	Study attrition (max. 15)	Prognostic factor measurement (max. 15)	Outcome measurement (max. 15)	Statistical analysis and reporting (max. 15)	Quality score (max. 75)
Gephart et al. (2014) [18]	15	5	12.5	15	15	62.5
Lee et al. (2016) [38]	15	5	12.5	12.5	15	60
Youn et al. (2015) [30]	15	5	12.5	12.5	15	60
Boo et al. (2012) [21]	15	5	12.5	10	15	57.5
Drenckpohl et al. (2010) [36]	15	5	10	12.5	15	57.5
Guthrie et al. (2003) [23]	15	5	10	12.5	15	57.5
Yee et al. (2012) [27]	15	5	12.5	10	15	57.5
Gagliardi et al. (2008) [28]	15	5	12.5	7.5	15	55
Manogura et al. (2008) [39]	15	5	10	10	15	55
Yamoto et al. (2016) [26]	15	5	10	10	15	55
Faustini et al. (2003) [37]	13.5	5	10	12.5	12.5	53.5
Carter et al. (2008) [22]	15	5	10	10	12.5	52.5
Luig et al. (2004) [25]	15	5	10	7.5	15	52.5
Uauy et al. (1991) [24]	12	5	10	10	12.5	49.5

NEC necrotizing enterocolitis, QUIPS quality in prognosis studies