Question

list and describe the basic steps of conducting a descriptive epidemiologic study

Answer 1

What is epidemiologic studies?

In the classic definition, accepted by worldover, epdemiological study is the "study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems". It is the dynamic study of the determinants, occurence, distribution, control and pattern of the health and disease in a population.
Thus it studies the nature of an epidemic, how it affects a population, and analyse it in the basis of person, place, age atc.. by observation and not by experimenting.

Classification of epidemiologic studies.

Epidemiologic studies can be broadly divided into two- Experimental/ Interventional studies and Non-experimental/ Observational studies. Descriptive studies comes under observational studies.

What are descriptive epidemiological study?

Descriptive epidemiological study is an investigation for finding the what/when/where/who analysis of an epidemis. It observes and study about a disease in the basis of the exposed place, person, the place it oiginated, the time of occurance, transmission method, causes of disease, how it occured and compare with unexposed people and places.

Thus we will get a detailed and comparitive study about the disease and thus prevent the further spreading of disease. The descriptive studies about CORONA gave vital data about its spreading and it helped to control it.

The main aim of conducting a descriptive epidemiology study;
• Alert people about an endemic and bioterrorism.
• Aware people about the nature of a disease.
• To set a control on epidemis and health issues from the data.

Types of descriptive studies;
• Case report
• Case series
• Surveillance studies
• Ecological studies

Steps in descriptive epidemiologic study;
The study involves 3 major steps- To find the place, valuate the person, to determine time.

• An epidemiologist become familiar with the data. Thus he knows the available data, its limitations, number of missing data etc..
• Then he studies about the extent and pattern of the health problem.
• He creates illustrations and graph about the information.
• From all these data, a hypothesis is formed.

PERSON: The decriptive data collection will analyse the age, sex, occupational status, race ,residence, health status, marital status etc.. of each person through questionnaaires, case studies etc..

PLACE: The place of origin, spreading and the ways and frequency of transmission etc..are analysed. Here the place wise study includes international level, national level, rural/urban level and the local pattern of distribution is analysed.

TIME: The time period or the pattern of occurence in the basis of time is analysed. It analyses seasonal or cyclical trend where the disease occur in specified season or time intervals.
Secular trend- It checks the secular trends to reduce the effect, spreading of a long term affecting disease.
Propogated epidemic period- The study reveals the porpogation period of a disease that helps us to get aware and take necessary precuations.
Common source epidemic- analyse whether it is point source single exposure where the spreading is too low and cases are less or continuous or multiple exposure which causes spreading.

The studies helps to give a 3 dimentional view of a disease and thus the publication of studies, awareness programs, precuations, casualities, change in lifestyle, scientific studies etc.. can be initiated.