疾病的时间分布是流行病学一项重要特征。分析疾病的时间分布,能加深对疾病流行动态的了解,并为进一步研究病因提供线索。影响疾病时间序列的因素甚多,但按其影响结果的性质主要有长期趋势、季节性变动、周期性变动和偶然变动等四种成分。时间序列分析的原理是将组成时间序列的各种成分分别进行解析,如欲求其中一种成 The time distribution of the disease is an important feature of epidemiology. An analysis of the time distribution of the disease can deepen the understanding of the dynamics of the disease and provide clues for further study of the cause. There are many factors that affect the time series of diseases. However, the nature of the outcome depends on long-term trends, seasonal changes, cyclical changes and accidental changes. The principle of time series analysis is to analyze the various components of the time series separately,