2.2. Population and Randomization
death, congenital malformations
CONGENITAL INFECTIONS, BLIND, INBORN ERRORS OF METABOLISM
We included all newborns with a gestational age (GA) <32 weeks or body birth weight (BW) <1500 g, consecutively admitted to the NICU of Policlinico Umberto I, La Sapienza University of Rome over a 4-year period. We excluded from the analysis neonates with major congenital malformations, inborn errors of metabolism, congenital infections, loss of central lines, hospital discharge or transfer or death within 24 h of life.Consecutive eligible patients were randomly assigned (1:1) to either one of the two PN protocols characterized by early (Group 1) or delayed (Group 2) achievement of the macronutrient target intake.Target intake was defined by the sum of macronutrient intake received by parenteral plus enteral nutrition. In both groups, the enteral nutrition protocol was administered according to a unique protocol. The nutritional protocol followed by patients included in the two study groups were reported in Patients were allocated to each group according to a software generated randomization list. Concealment of group assignment was ensured by the use of a computerized randomization system. On the randomization list, each patient was associated with a code belonging to either one of the two treatment protocols. A neonatologist in charge of PN prescription had to insert the specific code in the software that opened up either one of the group treatments. Performing a double-blind study would not have been ethically feasible, physicians prescribing the supplemental PN proposed by the software were unaware of the study aims and we used the third-party blind observer method to assess efficacy. Outcome assessors and investigators who were not directly involved in NICU patient care were not informed of treatment allocation. 