By the end of this lecture, the student will be
1. Understand the importance of epidemiology
in medical sciences by knowing some of its
2. Define epidemiology.
3. Describe the epidemiologic approach.
4. Enumerate the aims of epidemiology.
The definition of epidemiology
The study of the distribution and
determinants of health-related states or
events in specified populations, and the
application of this study to the prevention
and control of health problems
Observation, Surveillance, Hypothesis testing, Experiment
Time, Place, Person
Biological, Chemical, Social, Economic, Behavioural etc.
Entire populations, Groups of populations (Occupation, Residence,
Gender, Education etc.)
The Epidemiological Approach
1 Asking Questions
WHAT? WHERE? WHEN? WH0? HOW? WHY?
2 Making Comparisons
Aims of Epidemiology
• Describe distribution and magnitude of health
and disease problems in human populations.
• Identify etiological factors in disease
• Provide data essential to planning,
implementation and evaluation of services for
the prevention, control and treatment of
disease and to the setting up of priorities
among those services.