人群可按许多特征进行分组,如年龄、性别、民族、习惯等。这些特征有些在人出生时就已决定,终身不会改变,如年龄、性别、民族等。有些则在出生后可以随着环境的不同而发生变化,如职业、习惯等。许多传染病和非传染病的发病率、死亡率、病死率都可能和这些因素有关。掌握影响疾病分布的因素,有利于预防控制和消灭疾病。 Crowds can be grouped by many characteristics, such as age, gender, ethnicity, habits, etc. Some of these characteristics have been decided at birth and will not change over time, such as age, gender, ethnicity, etc. Some may change with the environment after birth, such as occupation, habits and so on. The incidence, mortality and mortality of many infectious and non-communicable diseases may all be related to these factors. Grasp the factors that affect the distribution of the disease, help prevent and control and eliminate the disease.