Table 1 Description of outcomes with analysis metric, aggregation method, and time points in main cohort
Outcome variables complete cohort | |||
|---|---|---|---|
Primary outcome variables | Analysis metrics | Method of aggregation | Time point |
Necrotizing enterocolitis | Incidence rate | Mean/Median | During study intervention (until 34 weeks of gestational age) |
Necrotizing enterocolitis Bell Stage >IIa Verified | Incidence rate | Mean/Median | During study intervention (until 34 weeks of gestational age) |
Necrotizing enterocolitis Bell Stage >IIIa Verified | Incidence rate | Mean/Median | During study intervention (until 34 weeks of gestational age) |
Necrotizing enterocolitis Operation | Date, time | Mean/Median | During study intervention (until 34 weeks of gestational age) |
Abdominal symptoms | Incidence of free gas, intermural intestinal gas, inflated abdomen discolored abdomen, stagnant intestinal loop >24 h | Sum | During study intervention (until 34 weeks of gestational age) |
Differential gastrointestinal diagnoses | Spontaneous intestinal perforation, Malrotation/volvulus, other | Sum | During study intervention (until 34 weeks of gestational age) |
X-ray of the abdomen | Incidence rate | Mean/Median | During study intervention (until 34 weeks of gestational age) |
Death | Incidence rate | Mean/Median | Third day postpartum until 40 weeks of gestational age |
Secondary outcome variables | |||
Late-onset sepsis | Incidence rate | Mean/Median | During study intervention (until 34 weeks of gestational age) |
Verified late-onset sepsisb | Incidence rate | Mean/Median | During study intervention (until 34 weeks of gestational age) |
Late-onset sepsis Culture-proven | Type of pathogen | Sum | During study intervention (until 34 weeks of gestational age) |
Late-onset sepsis date | Date of onset | Sum | During study intervention (until 34 weeks of gestational age) |
Late-onset sepsis Peripheral line at onset | Yes/No | Mean/Median | During study intervention (until 34 weeks of gestational age) |
Late-onset sepsis Central line at onset | Yes/No | Mean/Median | During study intervention (until 34 weeks of gestational age) |
Use of antibiotics | Rate of prescription (number) Duration of treatment (days) | Mean/Median | During study intervention and until 40 weeks of gestational age |
Length of stay | Number of days | Mean/Median | Length of stay at the neonatal intensive care unit Length of stay at homecare |
Effect on microbiome | Fecal samples | 1. Directly after inclusion ± 2 days 2. 14 ± 2 days gestational age 3. 34 weeks ± 2 days gestational age 4. 12 months corrected age ± 2 weeks | |
Serious adverse event (Necrotizing enterocolitis, death and late-onset sepsis included) | |||
Bronchopulmonary dysplasia | Yes/No | Mean/Median | During study intervention (until 34 weeks of gestational age) |
Respiratory distress syndrome | Yes/No | Mean/Median | From birth and during study intervention (until 34 weeks of gestational age) |
Patent ductus arteriosus (PDA) | Yes/No | Mean/Median | From birth and during study intervention (until 34 weeks of gestational age) |
Pulmonary hypertension | Yes/No | Mean/Median | During study intervention (until 34 weeks of gestational age) |
Intraventricular hemorrhage | Yes/No | Mean/Median | During study intervention (until 34 weeks of gestational age) |
Hydrocephalus | Yes/No | Mean/Median | During study intervention (until 34 weeks of gestational age) |
Retinopathy of prematurity | Yes/No | Mean/Median | During study intervention (until 34 weeks of gestational age) |
Characteristics/covariates | |||
Pregnancies | Number | Mean/Median | Baseline |
Preeclampsia | Yes/No | Mean/Median | Baseline |
Chorioamnionitis | Yes/No | Mean/Median | Baseline |
Infection pregnancy | Number of infections | Sum | Baseline |
Antibiotics during pregnancy | Period | Sum | Baseline |
Mode of delivery | Vaginal or Cesarean-section | Mean/Median | Baseline |
Apgar-score | At 1, 5 and 10 minutes | Mean/Median, Sum | Baseline |
Gender (x/y) | Boy/girl | Mean/Median | Baseline |
Multiple birth | Yes/No | Mean/Median | Baseline |
Gestational age | Number (gestation week) | Mean/Median | Baseline |
Birth weight | Kilograms | Mean/Median | Baseline |
Birth length | Centimeters | Mean/Median | Baseline |
Birth head circumference | Centimeters | Mean/Median | Baseline |
Z-scores from growth chart at birth | Standard deviation | Baseline | |
Respiratory support Intubation | Period of treatment | Mean/Median | From birth until 40 weeks of gestational age |
Respiratory support Continuous positive airway pressure (CPAP) | Period of treatment | Mean/Median | From birth until 40 weeks of gestational age |
Respiratory support High-flow nasal cannula | Period of treatment | Mean/Median | From birth until 40 weeks of gestational age |
Respiratory support Low-flow nasal cannula | Period of treatment | Mean/Median | From birth until 40 weeks of gestational age |
Patent ductus arteriosus closure strategies Paracetamol | Period of treatment | Mean/Median | From birth until 40 weeks of gestational age |
Patent ductus arteriosus closure strategies Operation | Date | Mean/Median, Sum | From birth until 40 weeks of gestational age |