Epidemiology Definitions
What is 'population medicine'?
The term population medicine is sometimes used as a synonym for the term epidemiology. It indicates that the techniques of epidemiology are applied to the entire population rather than specific individuals.
What do epidemiologists mean by the term 'determinants'?
The term ‘determinants' refers in epidemiologic language to causes of disease. Examples of determinants are fairly clear when we're speaking about infectious diseases. The common cold is caused by a virus. There are many bacterial agents that cause disease. The issue of determinants becomes clouded when we're speaking about many of the chronic diseases of long duration. For example, the determinants of many forms of cancer are unclear. In addition, some diseases have multiple determinants. For example, with coronary heart disease, heart disease mortality has more than a single determinant. The specific determinants that are involved and the way that they interact with one another clouds the picture of causality of disease.
What do epidemiologists mean by the term 'distribution'?
Well the term 'distribution' refers to the fact that diseases vary in populations according to the characteristics of the population. For example, the disease Tuberculosis is endemic in many parts of the world but not as frequent in the United States, although it is a significant problem. Many forms of chronic diseases, such as cancer or coronary heart disease, vary according to the distribution of the population in which they occur. Some groups---ethnic groups---may have reduced occurrence of some chronic diseases, such as cancer, because of lifestyle factors that prevent cancer from occurring.
What do epidemiologists mean by the term 'population'?
The population refers to entire group of people and it can have several definitions, depending on the frame of reference that one works with. For example we can speak of the population of the world; we can speak of the population of a specific country. Sometimes, we refer to the population of a state or a county. Or it can even be important sub-group, such as a University population of the students who are attending the University, or almost any group as defined by the epidemiologist.
What do epidemiologists mean by the term 'population at risk'?
The population at risk refers to those people who are specifically capable of coming down with the condition, or developing the condition, of interest. For example, we can give several good examples for many infectious diseases, if there is a specific immunization against that disease to protect the population, and then the individuals who have received the immunization generally will not be part of the population at risk. If we are talking about cervical cancer, women who have had a hysterectomy would not be a part of the population at risk for cervical cancer and so forth.
What do epidemiologists mean by the term 'morbidity'?
The term 'morbidity' refers to sickness in the population. For example, people who are afflicted with certain diseases and conditions. An example would be people who are afflicted with diabetes, Type I Diabetes, or people who are afflicted with the flu at any given time.
What do epidemiologists mean by the term 'mortality'?
Mortality refers to death and it is noteworthy for epidemiology, because it is an important outcome variable that is used in epidemiologic studies. Death is very clear cut, noted in important data sources such as death certificates and can be studied with some degree of clarity where as morbidity is often less clear.
What is 'biostatistics'?
The term biostatistics refers to the methods of statistics applied to biological problems. In many ways, biostatistics is similar or certainly a close relative of statistics that might be used in other disciplines. However, biostatistics has certain concerns in faux side that are applied specifically to health problems and public health problems. One example, is the calculation of survival peers would be an application of biostatistics, and how populations survive or some groups of a population, if they are given a specific treatment for a disease.
What does 'etiology' mean?
That is a very important feature of epidemiology. What are the etiologic features of cancer? What causes cancer? What causes diabetes? What causes the major chronic diseases? Epidemiology can often identify risk factors, which indicate increased probability of developing the disease within the population, but is often less able to identify specific etiologic factors for diseases.
What's the difference between 'incidence' and 'prevalence'?
The incidence of disease refers to new cases of disease. Incidence information is used to study risk to the population, and also to study the ideology of diseases. Prevalence of disease refers to the total number of cases of disease that exist in the population, either during a period of time or at a specific point in time. Incidence and prevalence are related terms. As the duration of disease increases, for example, the prevalence of the disease must increase as well.
What's the difference between a 'disease rate' and 'disease proportion'?
There's a very important distinction between the two. A "proportion" refers to a numerator expressed as a fraction of the entire population. In contrast, a "rate" has similar information that refers to the number of new cases of disease that occur as the fraction of the population, but also involves a time period during which the events occurred.
