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Table 2 Variables/outcomes to be presented and planned statistical analysis methods

From: Systemic Hydrocortisone To Prevent Bronchopulmonary Dysplasia in preterm infants (the SToP-BPD study): statistical analysis plan

Variable/outcome

Type of outcome

Statistical analysis

Study phase I: short-term outcomes until initial hospital discharge

BPD-free survival at 36 weeks PMA

Primary

Logistic regression with correction for stratification factors plus sensitivity and sub-group analyses

Death at 28 days PNA, at 36 weeks PMA and at hospital discharge

BPD at 36 weeks PMA

Failure to extubate 3, 7, 14 and 21 days after start of trial medication

Time to extubation, censored at death

Time to supplemental oxygen independence

Time to hospital discharge

Necrotising enterocolitis

Gastrointestinal bleeding

Spontaneous intestinal perforation

Intraventricular haemorrhage and/or periventricular leucomalacia

Retinopathy of prematurity

Hypertension

Hyperglycaemia requiring insulin therapy

Nosocomial infection, including clinical or culture-proven sepsis, meningitis, pneumonia

Patent ductus arteriosus needing medical intervention or surgical ligation

Weight, head circumference, length at 36 weeks PMA

Use of open-label HC treatment

Short-term secondary

Linear, logistic or Cox regression or competing risk model, as appropriate

SUSARs, SAEs

Short-term secondary

Descriptive statistics

Study phase II: long-term follow-up at 2 years CA

Survival without neurodevelopmental impairment

Key long-term secondary

Logistic regression with correction for stratification factors, sensitivity and sub-group analyses

Mortality

Number of hospital readmissions since first discharge to home

Cerebral palsy and its severity

Hearing loss requiring hearing aids

Blindness

Behaviour problems (Child Behavior Checklist)Growth (weight, length, head circumference)

Long-term secondary

Linear, logistic or Cox regression or competing risk model, as appropriate

  1. Abbreviations: BPD Bronchopulmonary dysplasia, CA Corrected age, HC Hydrocortisone, PMA Postmenstrual age, PNA Postnatal age, SAE Serious adverse event, SUSAR Suspected unexpected serious adverse drug reaction