Hylke Salverda

125 7 AOC for very preterm infants and neurodevelopmental outcome at two years Mild to moderate NDI was defined as cerebral palsy GMFCS level 1 or 2, Bayley-IIINL cognitive or motor scores below one standard deviation under the mean, mild visual and/or hearing impairment. Motor and cognitive development were assessed using the Bayley Scales of Infant and Toddler Development Third Edition, Dutch version (Bayley-III-NL).17, 18 As the minimum cognitive composite score using the Bayley III is 55, children failing to achieve this were nominally assigned a score of 54. Bayley III floor motor composite score is 46 hence children failing to achieve this were nominally assigned a score of 45.19 Visual impairment was classified as mild (needing treatment by an ophthalmologist or orthoptist), impaired vision with the ability to see or blind. Hearing loss was defined as mild, neurosensory hearing loss or deaf. Behavioural outcome was assessed using the Child Behavioural Checklist (CBCL 1.5–5years) completed by parents.20 A classification of level 3 or higher on the GFMCS was considered severe.16 When data could not be collected from the patient data management systems, The Dutch Perinatal and Neonatal register (Landelijke Neonatale Registratie) or other follow-up centres (university hospitals, revalidation centres) were consulted to complement the data. Oxygen titration During almost the entire study period the AVEA ventilator (Vyaire, Yorba Linda CA, United States) was used for respiratory support, after August 2015 this involved AOC by the CLiO2 (Closed Loop of inspired Oxygen) controller. 8 As of November 2018 newly born preterm infants were supported by the SLE6000 ventilator (SLE, London, United Kingdom) with the OxyGenie option for AOC.21 Following recent European guidelines,22 in November 2014 we changed the SpO 2 target range in our NICU from 85–95% to 90–95%. Data analysis Data are reported as mean (SD), median (range), or number (percentage) as appropriate, with standard tests for normality. Statistical comparison was executed using an independent t-test, a Mann-Whitney U test, and a chi-square or Fisher’s exact test as appropriate. Statistical analyses were performed using IBM SPSS Statistics for Windows, version 25 (IBM, Armonk, New York, USA). Two-sided p-values of < 0.05 were considered statistically significant.