According to the different observation time, the prevalence rate can be divided into two types: period prevalence rate and time-point prevalence rate. Prevalence rate is the most suitable index to calculate the status quo of chronic diseases.
Prevalence survey, also known as current situation study, is a survey of the distribution and correlation between health status (diseases or other health characteristics) and other related variables (environmental factors, living habits, etc.). ) for a certain group of people in a short time.
One of the epidemiological investigation methods. The commonly used methods are sampling survey and general survey. Prevalence survey is suitable for diseases with long course and high prevalence, such as tumors, cardiovascular diseases and endemic diseases. It is also suitable for the evaluation of the impact of environmental pollution on health.
Its advantages are convenience, economy, time saving, getting results in a short time and providing clues to the reasons; The disadvantage is that investigating health status, environment and other variables at the same time can only explain the situation at that time, and can not draw the conclusion of causality.
symptom
Refers to the signs that something is wrong with the outside of the body.
Pay attention to the difference between diseases and symptoms, and symptoms of diseases are synonymous with diseases.
example
Chinese medicine understands symptoms and makes a diagnosis by observing, smelling, asking and feeling.
Symptoms are superficial diseases, and what we want to know here is symptoms.