EPI Notes
An overview of epidemiology, its definition, key concepts like disease distribution and determinants, practical applications, and historical roots tracing back to Hippocrates.
Alice Edwards
Contributor
4.1
38
2 months ago
Preview (8 of 26)
Sign in to access the full document!
Chapter 1:
What is epidemiology?
The study of the distribution and determinants of disease frequency in human populations. (1970)
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.
Disease Distribution and Determinants
Disease distribution:
frequency and pattern of health events in a population
Determinants:
Any factor (event, characteristic, or other definable entity) that brings about a change in a health
condition.
What is Epidemiology? Application
Applying the knowledge gained by the studies to control the health problems.
• Cancer screening
• Health education
• Health promotion
History and Evolution of Epidemiology
Epi= on or upon
demi=people
ology= the study of; body of knowledge
Literally meaning "the study of what is upon the people"
History and Evolution of Epidemiology- Hippocrates:
Hippocrates:
• The father of medicine and the first epidemiologist.
• Describes the distinction between " epidemic " and "endemic";
endemic —> epidemic—> epidemiology
History and Evolution of Epidemiology
• In the early time, some described epidemiology as the study of epidemics
- An epidemic occurs when there are significantly more cases of the same disease than past experience
would have predicted.
Epidemiologic Triad for infectious disease
Host
Agent
Environment
Public Health
What is epidemiology?
The study of the distribution and determinants of disease frequency in human populations. (1970)
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.
Disease Distribution and Determinants
Disease distribution:
frequency and pattern of health events in a population
Determinants:
Any factor (event, characteristic, or other definable entity) that brings about a change in a health
condition.
What is Epidemiology? Application
Applying the knowledge gained by the studies to control the health problems.
• Cancer screening
• Health education
• Health promotion
History and Evolution of Epidemiology
Epi= on or upon
demi=people
ology= the study of; body of knowledge
Literally meaning "the study of what is upon the people"
History and Evolution of Epidemiology- Hippocrates:
Hippocrates:
• The father of medicine and the first epidemiologist.
• Describes the distinction between " epidemic " and "endemic";
endemic —> epidemic—> epidemiology
History and Evolution of Epidemiology
• In the early time, some described epidemiology as the study of epidemics
- An epidemic occurs when there are significantly more cases of the same disease than past experience
would have predicted.
Epidemiologic Triad for infectious disease
Host
Agent
Environment
Public Health
Public health is defined as the science of protecting the safety and improving the health of communities
through education, policy making and research for disease and injury prevention.
Why we study on epidemiology? Public Health
• Epidemiology is basic science of PUBLIC HEALTH;
• Epidemiology is a PUBLIC HEALTHapproach;
EPIDEMIOLOGY has the methodology to:
• Determine the extent of disease in the community;* Study the natural history and prognosis of
disease;
• Identify associations and potential etiology(causes) of a disease and risk factors for disease;
• Evaluate new preventive and therapeutic measures and new modes of health care delivery
In summary, it may provide a basis for public health initiatives and policies.
Epidemiology and Prevention
Risk factors
• Modifiable risk factors
• Non-modifiable risk factors
High risk population
• Three types of prevention
Primary prevention
Secondary prevention
Tertiary prevention
Primary Prevention:
Prevention of disease by controlling risk factors (e.g., non-smoking promotion; vaccination; lifestyle
changes)
Etiologic Study
How can we know those risk factors?
• It is the most fundamental application of epidemiology;
• It aims to identify etiologic (causal) associations between exposure(s) and outcome(s)
Secondary prevention:
Reduction in consequences of disease by early diagnosis and treatment
(e.g., pap smear for cervical cancer screening Mammography for breast cancer etc.)
• Screening high risk population
• Diagnostic tests
through education, policy making and research for disease and injury prevention.
Why we study on epidemiology? Public Health
• Epidemiology is basic science of PUBLIC HEALTH;
• Epidemiology is a PUBLIC HEALTHapproach;
EPIDEMIOLOGY has the methodology to:
• Determine the extent of disease in the community;* Study the natural history and prognosis of
disease;
• Identify associations and potential etiology(causes) of a disease and risk factors for disease;
• Evaluate new preventive and therapeutic measures and new modes of health care delivery
In summary, it may provide a basis for public health initiatives and policies.
Epidemiology and Prevention
Risk factors
• Modifiable risk factors
• Non-modifiable risk factors
High risk population
• Three types of prevention
Primary prevention
Secondary prevention
Tertiary prevention
Primary Prevention:
Prevention of disease by controlling risk factors (e.g., non-smoking promotion; vaccination; lifestyle
changes)
Etiologic Study
How can we know those risk factors?
• It is the most fundamental application of epidemiology;
• It aims to identify etiologic (causal) associations between exposure(s) and outcome(s)
Secondary prevention:
Reduction in consequences of disease by early diagnosis and treatment
(e.g., pap smear for cervical cancer screening Mammography for breast cancer etc.)
• Screening high risk population
• Diagnostic tests
Tertiary prevention:
Reduction in complications of disease; limits the progression of disability;
treatment of symptoms and rehabilitation.
• Prognosis
• Survival analysis
Examples of Clinical Practice uses population data
• Criteria of diagnoses are usually defined and determined from large groups of patients.
Prognosis is based on experience of large groups of patients with the same disease, stage of disease, and
treatments.
Selection of therapy is based on the results of large treatment studies, such as clinical trials.
Epidemiology and Clinical Practice
Epidemiology is critical not only to public health but also to clinical practice. —> clinical epidemiology
Epidemiology and basic medical/biological science
• Epidemiology may provide clues from population for further medical or biological research;
• Results from medical or biological research also needs to be verified in population.
• Examples: Epidemiologic studies found use of low dose aspirin is associated with reduced risk of colon
cancer.
Then the researchers in basic science further demonstrated that the biological pathway from aspirin to
colon cancer through in vitro and in vivo studies.
Study Types of Epidemiologic research
Experimental- descriptive and analytical
observational- descriptive and analytical
Descriptive and Analytic Epidemiology
Descriptive epidemiology:
-When was the population affected?
-Where was the population affected?
-Who was affected?
Analytic epidemiology:
-How was the population affected?
-Why was the population affected?
Descriptive epidemiology
• Descriptive epidemiology is antecedent to analytical epidemiology.
Time (when)
Place (where)
Person (who)
Reduction in complications of disease; limits the progression of disability;
treatment of symptoms and rehabilitation.
• Prognosis
• Survival analysis
Examples of Clinical Practice uses population data
• Criteria of diagnoses are usually defined and determined from large groups of patients.
Prognosis is based on experience of large groups of patients with the same disease, stage of disease, and
treatments.
Selection of therapy is based on the results of large treatment studies, such as clinical trials.
Epidemiology and Clinical Practice
Epidemiology is critical not only to public health but also to clinical practice. —> clinical epidemiology
Epidemiology and basic medical/biological science
• Epidemiology may provide clues from population for further medical or biological research;
• Results from medical or biological research also needs to be verified in population.
• Examples: Epidemiologic studies found use of low dose aspirin is associated with reduced risk of colon
cancer.
Then the researchers in basic science further demonstrated that the biological pathway from aspirin to
colon cancer through in vitro and in vivo studies.
Study Types of Epidemiologic research
Experimental- descriptive and analytical
observational- descriptive and analytical
Descriptive and Analytic Epidemiology
Descriptive epidemiology:
-When was the population affected?
-Where was the population affected?
-Who was affected?
Analytic epidemiology:
-How was the population affected?
-Why was the population affected?
Descriptive epidemiology
• Descriptive epidemiology is antecedent to analytical epidemiology.
Time (when)
Place (where)
Person (who)
Loading page 6...
Loading page 7...
Loading page 8...
5 more pages available. Scroll down to load them.
Preview Mode
Sign in to access the full document!
100%