Table 5

Model most accurately describing the association between LoS and perinatal variables of surviving infants

Model dependent variable
LoS at the NICU (days)
Model: dependent variable
verall LoS (days) hospital (NICU+level II)
Coefficient of the model with 95% CICoefficient of the model with 95% CI
Constant14.912.9 to 16.948.245.9 to 50.5
FactorsAdditional days of admission on top of ‘constantAdditional days of admission on top of ‘constant
SGA2.30.6 to 3.97.42.8 to 12.1
Multiplet2.00.6 to 3.5
Period 2−1.2−3.1 to −0.82.0−0.9 to 4.9
Period 31.9−0.1 to 3.95.12.2 to 8.0
CLD35.232.4 to 38.130.526.6 to 34.4
NECs−2.2−11.7 to 7.8−4.2−15.6 to 7.3
PHVD intervention18.411.7 to 25.014.37.1 to 21.6
ROP intervention38.131.1 to 45.129.622.0 to 37.3
Late-onset sepsis5.23.5 to 6.95.93.6 to 8.1
Discharge to post-IC/HC department−3.2−4.6 to −1.7
Extra days CLD period 24.40.9 to 7.99.14.3 to 13.9
Extra days CLD period 35.51.9 to 9.18.23.3 to 13.1
Extra days NECs period 216.54.4 to 28.634.120.4 to 47.7
Extra days NECs period 35.8−5.9 to 17.5−0.9−14.8 to 12.9
Extra days SGA period 2−6.3−12.0 to −0.5
Extra days SGA period 3−7.9−13.9–−1.9
  • Model LoS at the NICU.

  • LoS (days)=14.9+(2.3*SGA)+(2.0*Multiplet)+(−1.2*Period 2)+(1.9*Period 3)+(5.2*late-onset sepsis)+(−2.2*necrotising encerocolitis with laparotomy)+(16.5*Period 2*necrotising encerocolitis with laparotomy)+(5.8*Period 3*necrotising encerocolitis with laparotomy)+(18.4*PHVD with intervention)+(35.2*CLD)+(4.4*Period 2*CLD)+(5.5*Period 3*CLD)+(38.1*ROP with intervention)+(−3.2*discharge to post-IC/HC).

  • Model overall LoS.

  • LoS (days)=48.2+(7.4*SGA)+(−6.3*Period 2*SGA)+(−7.9*Period 3*SGA)+(2.0*Period 2)+(5.1*Period 3)+(5.9*late-onset sepsis)+(−4.2*necrotising encerocolitis with laparotomy)+(34.0*Period 2*necrotising encerocolitis with laparotomy)+(−0.9*Period 3*necrotising encerocolitis with laparotomy)+(14.3*PHVD with intervention)+(30.5*CLD)+(9.1*Period 2*CLD)+(8.2*Period 3*CLD)+(29.6*ROP with intervention).

  • CLD, chronic lung disease; IC/HC, intensive care/high care; LoS, length of stay; NEC, necrotising enterocolitis with indication for surgery; NICU, neonatal intensive care unit; PHVD, posthaemorrhagic ventricle dilatation; ROP, retinopathy of prematurity; SGA, small for gestational age.