Medical University of Plovdiv, Plovdiv, Bulgaria.
Folia Med (Plovdiv). 2022 Aug 31;64(4):624-632. doi: 10.3897/folmed.64.e65957.
Varicella is an acute, highly contagious disease, characterised by generalised vesicular exanthema caused by the initial infection with varicella zoster virus (VZV) which usually affects children aged 2 to 8 years.
To analyse the changes of varicella incidence in Bulgaria over the period of 1928-2019.
The time series analysis is based on the official data for varicella incidence (per 100,000) in Bulgaria for ninety-two years (1928-2019), obtained from three major sources. We utilized the method to construct a time series model of overall incidence (1928-2019) using time series modeller in SPSS v. 25. We followed all three steps of the standard ARIMA methodology to establish the model - identification, parameter estimation, and diagnostic checking.
Stochastic scalar time series modelling of the varicella incidence from 1928 to 2019 was performed. The stochastic ARIMA (0,1,1) was identified to be the most appropriate model. The decomposition of varicella incidence time series into a stochastic trend and a stationary component was reasoned based on the model defined. In addition, we assessed the importance of the long-term and immediate effect of one shock. The long-term forecast was also under discussion.
The ARIMA model (0,1,1) in our study is an adequate tool for presenting the varicella incidence trend and is suitable to forecast near future disease dynamics with acceptable error tolerance.
水痘是一种急性、高度传染性疾病，其特征为全身性水疱疹，由水痘带状疱疹病毒（VZV）初次感染引起，通常影响 2 至 8 岁的儿童。
分析 1928 年至 2019 年保加利亚水痘发病率的变化。
时间序列分析基于保加利亚 92 年来（1928-2019 年）水痘发病率（每 10 万人）的官方数据，这些数据来自三个主要来源。我们使用时间序列建模器在 SPSS v.25 中构建了一个总体发病率（1928-2019 年）的时间序列模型。我们遵循 ARIMA 方法的所有三个步骤来建立模型-识别、参数估计和诊断检查。
对 1928 年至 2019 年水痘发病率进行了随机标量时间序列建模。确定随机 ARIMA（0,1,1）是最合适的模型。基于所定义的模型，对水痘发病率时间序列进行随机趋势和稳定分量的分解。此外，我们评估了一次冲击的长期和即时影响的重要性。还讨论了长期预测。
本研究中的 ARIMA 模型（0,1,1）是一种用于呈现水痘发病率趋势的合适工具，并且适合以可接受的误差容限预测近期疾病动态。
