2. 2
• Epidemiology is scientific discipline of public health to
study diseases in the community to acquire knowledge
for health care of the society
3. 3
• Epidemiological principles and methods are applied in :
Clinical research
Disease prevention
Health promotion
Health protection
Health services research
• The results of epidemiological studies are also used by other
scientists, including health economists, health policy analysts,
and health services managers.
5. 5
Definition
“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”
John M. Last (1988)
7. 7
Aim of Epidemiology
1. To eliminate or reduce the health problems of
community.
2. To promote the health and well-being of society as a
whole.
8. 8
Objectives of Epidemiology
1. To describe the distribution and magnitude of health and
disease problems in human population.
2. To identify etiological factors (risk factors) in the
pathogenesis of disease.
3. To provide data essential to the planning,
implementation and evaluation of services for the
prevention, control and treatment of disease and setting
priorities among those services.
9. 9
Distribution
• Distribution of disease occurs in a pattern.
• PATTERN- Time, Place, Person .
Hypothesis for Causative/Risk factor – Etiological
Hypothesis.
Descriptive Epidemiology.
10. 10
Determinants
• Identifying the causes and risk factors for diseases.
• Testing the Hypothesis – (Biostatistics)
• Analytical Epidemiology
11. 11
Scope of Epidemiology
1. Causation of the disease.
2. Natural history of the disease.
3. Health status of the population.
4. Evaluation of Interventions.
12. 12
1. Causation of the disease.
• Most of diseases are caused by interaction between genetic and
environmental factors. (Diabetes)
• Personal behaviors affect this interplay.
• Epidemiology is used to study their influence and the effects of
preventive interventions through health promotion.
14. 14
2. Natural History Of The
Disease
Epidemiology is also concerned with the course and outcome
(natural history) of diseases in individuals and groups.
16. 16
3. Health Status Of The
Population
• Epidemiology is often used to describe the health status of
population.
• Knowledge of the disease burden in populations is essential for
health authorities.
• To use limited resources to the best possible effect by
identifying priority health programs for prevention and care.
18. 18
4. Evaluation of Interventions
• To evaluate the effectiveness and efficiency of health services.
This means determining things such as –
Impact of Contraceptive use on Population Control.
The efficiency of sanitation measures to control diarrheal
diseases and
The impact of reducing lead additives in petrol.
20. 20
Applying epidemiological principles and methods to problems
encountered in the practice of medicine has led to the
development of :
“Clinical Epidemiology”
21. 21
Applications Of Epidemiology
In Public Health
• Preventing disease and promoting health.
• Community health assessment (Community Diagnosis) and
priority setting.
• Improving diagnosis, treatment and prognosis of clinical
diseases.
• Evaluating health interventions and programs
22. 22
Epidemiology And Public
Health
• Public health, refers to collective actions to improve
population health.
• Epidemiology, one of the tools for improving public health, is
used in several ways.
23. 23
• Primary health care (PHC) became a core policy for the World
Health Organization with the Alma-Ata Declaration in 1978 and
the ‘Health-for-All by the Year 2000’ Program.
• The commitment to global improvements in health, especially
for the most disadvantaged populations, was renewed in 1998
by the World Health Assembly. This led to the ‘Health-for-All
for the twenty-first Century’ policy and program, within which
the commitment to PHC development is restated.
24. 24
What Is Primary Health
Care?
• Essential health care
• First Level
• Socially appropriate
• Universally accessible
• Scientifically sound
• Trained workforce
• Integrated referral systems
26. 26
Primary Health Care Include :
• Health promotion
• Illness prevention
• Care of the sick
• Advocacy
• Community development
27. 27
PHC is:
Essential health care based on practical, scientifically
sound and socially acceptable methods and technology
made universally accessible to individuals and families in
the community through their full participation and at a cost
that community and the country can afford …
(Alma-Ata, 1978)
28. 28
Principles For PHC
PHC based on the following principles :
• Social equity
• Nation-wide coverage
• Self-reliance
• Inter-sectoral coordination
• People’s involvement in the planning and implementation of
health programs
29. 29
The 1978 Declaration of Alma-Ata proposed a set of PRINCIPLES for
primary health care. PHC should:
1. “Reflect and evolve from the economic conditions and socio-
cultural and political characteristics of the country and its
communities, and be based on the application of the relevant
results of social, biomedical and health services research and
public health experience”
2. “Address the main health problems in the community, providing
promotive, preventive, curative and rehabilitative services
accordingly”
30. 30
3. “Involve, in addition to the health sector, all related
sectors and aspects of national and community
development, in particular agriculture, animal husbandry,
food, industry, education, housing, public works,
4. “Promote maximum community and individual self-
reliance and participation in the planning, organization,
operation and control of primary health care, making fullest
use of local, national and other available resources; and to
this end develop through appropriate education the ability
of communities to participate”
31. 31
5. “Be sustained by integrated, functional and mutually-supportive
referral systems, leading to the progressive improvement of
comprehensive health care for all, and giving priority to those most in
need”
6. “Rely, at local and referral levels, on health workers, including
physicians, nurses, midwives, auxiliaries and community workers as
applicable, as well as traditional practitioners as needed, suitably
trained socially and technically to work as a health team and to respond
to the expressed health needs of the community.”
32. 32
Core Activities for PHC
Often health is considered as absence of certain disease conditions and not a condition
itself, which is not true
33. 33
1. Education concerning prevailing health problems and the
methods of preventing and controlling them
2. Promotion of food supply and proper nutrition
3. An adequate supply of safe water and basic sanitation
4. Maternal and child health care, including family planning
5. Immunization against the major infectious diseases
6. Prevention and control of locally endemic diseases
34. 34
7. Appropriate treatment of common diseases and injuries
8. Basic laboratory services and provision of essential
drugs
9. Training of health guides, health workers and health
assistants.
10. Referral services
35. 35
WHO Strategies Of PHC
1. Reducing excess mortality of poor marginalized
populations:
PHC must ensure access to health services for the
most disadvantaged populations, and focus on
interventions which will directly impact on the major
causes of mortality, morbidity and disability for
those populations
36. 36
2. Reducing the leading risk factors to human health:
PHC, through its preventative and health promotion roles,
must address those known risk factors, which are the major
determinants of health outcomes for local populations.
3. Developing Sustainable Health Systems:
PHC as a component of health systems must develop
in ways, which are financially sustainable, supported
by political leaders, and supported by the populations
served.
37. 37
4. Developing an enabling policy and institutional
environment:
PHC policy must be integrated with other policy
domains, and play its part in the pursuit of wider
social, economic, environmental and development
policy.
38. 38
The Basic Requirements for
Sound PHC (the 8 A’s and the 3
C’s)
• Accountability
• Completeness
• Comprehensiveness
• Continuity
• Appropriateness
• Availability
• Adequacy
• Accessibility
• Acceptability
• Affordability
• Assess ability
39. 39
Appropriateness
1. Whether the service is needed at all in relation to
essential human needs, priorities and policies.
2. The service has to be properly selected and carried
out by trained personnel in the proper way.
40. 40
Adequacy
1. The service proportionate to requirement.
2. Sufficient volume of care to meet the need and
demand of a community
43. 43
Acceptability
• Acceptability of care depends on a variety of factors,
including satisfactory communication between health
care providers and the patients, whether the patients
trust this care, and whether the patients believe in the
confidentiality and privacy of information shared with
the providers.
47. 47
Completeness
• Completeness of care requires adequate attention to
all aspects of a medical problem, including prevention,
early detection, diagnosis, treatment, follow up
measures, and rehabilitation.
49. 49
Continuity
• Continuity of care requires that the management of a
patient’s care over time be coordinated among
providers.
50. 50
Summary
Primary care is an approach that:
• Focuses on the person not the disease, considers all
determinants of health
• Integrates care when there is more than one problem
• Uses resources to narrow differences
51. 51
Summary
• Forms the basis for other levels of health systems
• Addresses most important problems in the community
by providing preventive, curative, and rehabilitative
services
• Organizes deployment of resources aiming at
promoting and maintaining health.
