How Does Epidemology Help Us to Know the Health Status of the Community

Epidemology is the study of how often diseases occur in different groups of people and why. Epidemiological information is used to plan and evaluate strategies to prevent information is used to lan and evaluate strategies to prevent illness and as a guide to the management of patients in whom disease has already developed.

Like the clinical findings and pathology, the epidemiology of a disease is an integral part of its basic description. The subject has its special techniques of data collection and interpretation, and its necessary jargon for technical terms.

The distribution of disease occurs in patterns in a community. In epidemiology we study these distribution patterns in various subgroups of the population by time, place and person; that is:

A. Whether there is an increase or decrease of disease over time; whether there is a higher concentration of disease in one geographic area than in others.

B. Whether the disease occurs more often in Men or in a particular age-group, and characteristic of those affected and not affected.

C. Study of these patterns may suggest or lead to measure to control or prevention of disease. Also one can formulate an etiological hypothesis of disease through these "descriptive epidemiology". Study of Epidemiology helps us in measuring the spread of disease, affected persons, how to prevent the disease from spreading.

TYPES OF EPIDEMOLOGICAL STUDIES

A. Observational studies

I. Descriptive Studies

a) Case reports

b) Case series

c) Ecological / Co relational

d) Cross- sectional/ prevalence

II. Analytical studies

a) Case control/case reference

b) Cohort/follow up

B. Experimental studies/Intervention studies

a) Randomized controlled trials/ Clinical trials

b) Field trials/ Community intervention trials

c) Community trials

Descriptive Studies: Epidemiological investigations often start with case reports and evolve to become a series of cases.

Procedures involved in descriptive studies are:

1. Defining the population and disease under study

2. Describing the disease by time, place and person

3. Measuring the disease ( in terms of incidence/ prevalence) comparing with known indices and formulating an etiological hypothesis.

Despritive epidemiology may use a cross-sectional or longitudinal design to obtain estimates of cross section of population at one point of time. In longitudinal