The document discusses the epidemiological approach and methods. There are two basic approaches: asking questions and making comparisons. Asking questions involves identifying health problems, who is affected, when and where issues occur, contributing factors, and actions that can be taken. Comparisons can be made between populations, subgroups, and time periods. Epidemiological studies systematically collect and analyze health data to describe problems, identify associated factors, and form hypotheses. There are two main types of studies: observational studies that observe groups without intervention and experimental studies that introduce a treatment to evaluate effectiveness compared to standard care.

1. Epidemiological Approach &
Methods
BY: Mr. Jagan Kumar Ojha
MSC. Tutor, SNC, SO DTU

2. Epidemiological Approach
The epidemiological investigation to health
problems involves the two basic approaches:
a.Askingquestions
b.Makingcomparisons

3. a. Asking Questions
 Epidemiology has been defined as a means of
learning or asking questions.. and getting answers that
lead to further questions.
 The key information can be approached through a
series of questions.
Related to health events
 What are the actual and potential health problems, its
manifestations and characteristics?
 Who are affected with reference to age, sex, social class..?
 Where did it occurs in terms of place?
 Which populations are increased at risk?

4. Related to health events….
 When does it happen in terms of day, month,
season etc..?
 Why does it happen in terms of contributing or
causative factors?
 Which problems have declined?
 Which problems are increasing or have the risk to
increase?

5. Related to health action
 What can be done to reduce the problem and its
consequences?
 How can it be prevented in the future?
 What action should be taken by the community/
by the health services/ other sectors to prevent
and manage the problem?

6. Related to health action…
 Where and for whom these activities carried
out?
 What resources are required in future? How are
the activities to be organized?
 What difficulties may arise, and how it has to be
overcome?

7. This approach is to make comparisons and draw
inferences.
Comparison may be made :
Between different population at a given time
eg. Rural with urban population
Between sub group of population
eg. Male with female population
Between various periods of observation
eg. Different seasons
b. Making Comparisons

8. b. Making Comparisons

10. Methods of Epidemiology
 Epidemiological study requires systematic collection
of health data, its analysis, description of health needs
and health problems, identification of factors
associated with the problems and stating the
hypothesis.

12. Observational studies
Observational studies are those in which people are
observed in their natural state. The researchers simply
"observe" a group of people without actually "doing"
anything to the study group. People may be monitored
overtime and significant details recorded, but no
intervention is introduced.
Methods of Epidemiology

13. Experimental studies
Experimental studies, commonly referred to as
clinical trials, are studies in which a treatment (or
procedure) is intentionally introduced by the researcher/
epidemiologist and a result (or outcome) is observed.
The aim of these types of studies is to evaluate the
effectiveness of a new treatment/ intervention in
comparison with the current standard of care.
Methods of Epidemiology