Data Associated with the Publication: Vital Sign Metrics of VLBW Infants in Three NICUs: Implications for Predictive Algorithms

This repository contains the dataset and code for the manuscript: Zimmet AM, Sullivan BA, Fairchild KD, Moorman JR, Isler JR, Wallman-Stokes AW, Sahni R, Vesoulis ZA, Ratcliffe SJ, Lake DE. Vital Sign Metrics of VLBW Infants in Three NICUs: Implications for Predictive Algorithms. Pediatric Research 2021. https://doi.org/10.1038/s41390-021-01428-3. EXPLANATION OF DATA FILES AND CODE To understand all of the included data files and to tell you which key files do what, review the ReadMe_VitalSignMetrics_20200226.txt file. HOW TO USE THE CODE After reviewing ReadMe_VitalSignMetrics_20200226.txt file, follow the entire code progression from raw data (the raw data itself could not be published), to summary data (included in this repository), through figure generation, via the script Pipeline.m. ABSTRACT Background: Continuous heart rate (HR) and oxygenation (SpO2) metrics can be useful for predicting adverse events in very low birth weight (VLBW) infants. To optimize the utility of these tools, inter-site variability must be taken into account. Methods: For VLBW infants at three NICUs, we analyzed the mean, standard deviation, skewness, kurtosis, and cross-correlation of electrocardiogram HR, pulse oximeter pulse rate, and SpO2. The number and durations of bradycardia and desaturation events were also measured. Twenty-two metrics were calculated hourly, and mean daily values were compared between sites. Results: We analyzed data from 1,168 VLBW infants from birth through day 42 (35,238 infant-days). HR and SpO2 metrics were similar at the three NICUs, with mean HR rising by ~10 beats/minute over the first two weeks and mean SpO2 remaining stable around 94% over time. The number of bradycardia events was higher at one site, and the duration of desaturations was longer at another site. Conclusion: Mean HR and SpO2 were generally similar among VLBW infants at three NICUs from birth through six weeks of age, but bradycardia and desaturation events differed in the first two weeks after birth. This highlights the importance of developing predictive analytics tools at multiple sites.

本仓库包含对应学术论文的数据集与配套代码，论文信息如下：Zimmet AM、Sullivan BA、Fairchild KD、Moorman JR、Isler JR、Wallman-Stokes AW、Sahni R、Vesoulis ZA、Ratcliffe SJ、Lake DE，论文标题为《三家新生儿重症监护病房极低出生体重婴儿的生命体征指标：对预测算法的启示》，发表于《儿科研究》2021年，DOI: 10.1038/s41390-021-01428-3。

### 数据文件与代码说明
为明晰本仓库内所有数据文件的用途并说明核心文件的功能，请查阅ReadMe_VitalSignMetrics_20200226.txt文件。

### 代码使用方法
查阅ReadMe_VitalSignMetrics_20200226.txt文件后，请通过Pipeline.m脚本完整遵循代码流程：从原始数据（原始数据无法公开发布）出发，至本仓库收录的汇总数据，最终完成图表生成。

### 摘要
**背景**：连续心率（Heart Rate, HR）与血氧饱和度（Pulse Oximetry Oxygen Saturation, SpO2）指标可用于预测极低出生体重（Very Low Birth Weight, VLBW）婴儿的不良临床事件。为优化此类工具的实用价值，需纳入不同医疗中心间的异质性差异。
**方法**：针对三家新生儿重症监护病房（Neonatal Intensive Care Unit, NICU）收治的VLBW婴儿，我们分析了心电图心率、脉搏血氧仪脉率及SpO2的均值、标准差、偏度、峰度与互相关系数，并测量了心动过缓与低氧血症事件的发生数量及持续时长。每小时计算22项生理指标，并对比各医疗中心的日均指标值。
**结果**：我们分析了1168名VLBW婴儿从出生至第42天的共计35238个婴儿日数据。三家NICU的HR与SpO2指标总体相似：平均心率在最初两周内上升约10次/分钟，平均SpO2随时间稳定维持在94%左右。其中一家医疗中心的心动过缓事件发生率更高，另一家的低氧血症持续时长更长。
**结论**：出生后六周内，三家NICU收治的VLBW婴儿的平均心率与SpO2总体相似，但出生后前两周的心动过缓与低氧血症事件存在显著差异。这凸显了在多医疗中心场景下开发预测分析工具的重要性。