Hylke Salverda

91 5 Comparing statistics from one-per-minute and one-per-second data Introduction The wealth of routinely collected data in Neonatal Intensive Care Units (NICUs) has great potential. Morbidities such as bronchopulmonary dysplasia, retinopathy of prematurity and sepsis can possibly be predicted when coupling analyses of routinely measured vital signs or derivatives with outcomes. One example is the HeRO symphony system predicting sepsis from variability of heart rate.1 In real time, algorithms can summarize relevant data, detect anomalies and notify bedside staff of risk factors for certain diseases. Routinely collected data could be used to develop algorithms or find associations retrospectively. However, it is unclear at what frequency data should be sampled. In our NICU, data is often sampled at least once per second (one-per-second data, f.e. 1 heart rate value per second) for prospective studies, but routinely collected vital parameters are only sampled once per minute (one-per-minute data). This keeps up performance of the clinical patient data management system, and prevents high costs associated with storage of data. Other NICUs may have similar infrastructure in place with data already collected and available. Although the data could be collected at a higher frequency, it is unclear whether lower frequency data is already enough. We hypothesized that lower frequency data could in some cases be sufficient to run retrospective studies. In this short report we investigated what to expect when using one-per-minute data abstracted from one-per-second data and investigated under what conditions one-per-minute data could be used. Materials and methods Routinely collected data froma previous study was used, the ethical review committee of Leiden Den Haag Delft provided a statement of no objection for obtaining and publishing the anonymized data (G19.075).2 Data recordings were included from infants born under 30 weeks of gestation in our tertiary-level perinatal center between November 1st 2018 and March 15th 2020. Recordings were excluded if they contained no data on peripherally measured oxygen saturation (SpO2). Data collection and outcome measures Parameters collected were 2-4s averaged SpO2 measured by a weight-appropriate pulse-oximeter probe (LNCS Neo Masimo SET; Masimo Irvine, California, USA), and measured inspiratory fraction of oxygen (FiO2). These data were sent from a