The study of distribution and determinats of health related states or events in specific population and application of this study to the control of health problems.
Components of epidemiology
- Frequency of disease. It includes measurement of frequency of disease, disability or death and summarizing this information in the rates and ratios.
- Distribution of disease. By the time, place and person.
- Determinants of disease. It includes identify the underlying cause of disease by analytic study.
Amis of epidemiology:
- . To describe the distribution and magnitude of health and disease in human population.
- . To identify the risk factor in the pathogenesis of disease
- . To provide data essential to the planning.
- . Implantation and evaluation of services for the prevention, control and treatment of disease and to the setting up of priorities among those service.
- Use of epidemiology.
- . To study history of disease.
Health and disease pattern in community is never constant. There is fluctuations both over short and long period of time. Epidemiology provides a means to study these trends.
. Community diagnosis.
It refer to the identification and quantification of health problems in community in term of mortality and morbidity rates and ratios.
. Planning and Evaluation.
Planning is important for the allocation of the limited resources. Epidemiologic information about the distribution of health problems over a time and place provides a fundamental basis for planning and developing the needed health service and assessing the impact of these service on the people health problems. Evaluation is equally important concern of epidemiology.
.Evaluation of individual risk and chances.
On of the important task of epidemiologist is to make a statement about the degree of risk in population.
. Syndrome identification.
Medical syndromes are identified by observing frequently associated finding I’m individual patients. Epidemiologic study can be used to defined and refine syndromes.
. Completing the natural history of disease.
Epidemiologic study have yielded a large amount of data on a risk factor in relation to chronic diseases.
. Searching for causes and risk factors.
Epidemiologist try to identify the cause of disease by Epidemiologic investigation. For example. Identifying that rubella is the cause of congenital defect.
. Thalidomide is a teratogenic agent.
. Cigarette smoking is the cause of lung cancer.
Basic measures in Epidemiology.
The scope of measurement in epidemiology is very broad and unlimited and includes the following.
. Measurement of mortality.
. Measurement of morbidity.
. Measurement of disability.
. Measurement of Natality.
. Measurement of the presence , absence and distribution of disease.
. Measurement of presence, absence and distribution of environmental factor suspected of the cause of diseases.
. Measurement of demographic variables.
The basic requirements of measurement are validity, reliability , accuracy, sensitivity and specificity.