EPIDEMIOLOGY SUMMARY AND QUESTION
Public Health - the science and art of preventing disease, prolonging life and promoting health through
organized efforts in society
Model for public health - -definition of the problem
-magnitude of the problem
-identification & understanding determinants
-develop medical or behavioral interventions/ prevention strategies (recommendation)
-set policy or public health priorities
-implement and evaluate
Surveillance - tracking of a disease
Epidemiology - the study of the distribution and determinants of health-related states or events in
specified populations and the application of this study to control health problems
Objectives of epidemiology - -identify the causes of disease (etiology)
-study of the natural history and prognosis
-determine the overall size of the problem in the community (prevalence) or measure how quickly it is
growing in the community (incidence)
Uses of Epidemiology evidence - 1. changing patterns of community health
2. developing and evaluating prevention programs
3. clinical practice
Changing patterns of disease - -epidemiologic shift
-infectious to chronic
,Prevention - -identification of high risk groups
*define how and why they are high-risk and potentially modify those factors before they acquire the
disease
*direct preventative measures to those high-risk groups most likely to benefit
types of prevention - *primary->prior to the disease occurring->vaccines
*secondary->early detection of existing disease to reduce severity and complications->screening, breast
exams
*tertiary->reducing impact of disease, no cure->rehab
Clinical practice - -the practice of medicine, although focused on one patient, is dependent of
population data
*diagnosis and screening
*prognosis
*selection of therapy
U.S. preventative task force - -recommendations on effectiveness of clinical preventative services for
those without symptoms
-recommendations based on evidence of both the benefits and harms and an assessment of balance
-recognizes clinical decisions involve more considerations than evidence alone
*clinicians should understand evidence but make decisions for the specific patient
*notes that policy and coverage decisions involve other considerations
Characteristics of epidemiology - -primarily a quantitative methodology that includes reasoning
-can be considered a basic science of public health
*biostats also shares these characteristics
What influences transmission? - 1. Interaction between host and agent, environment, and vector
2. mode of disease transmission
3. distribution of the severity of disease in the community
, 4. level of disease-to-immunity in the community
epidemiologic triad - interaction between host, agent, vector and the environment
modes of transmission - ways by which disease is passed within a community
Types of transmission - 1. direct-person to person contact
2. indirect-common vehicle, (single, multiple, continuous exposure), vector
Mode of transmission: Maternal to child - -vertical transmission of disease causing agents from mother
to child during:
*pregnancy, delivery or just after birth
*breastfeeding
*infections
-ALL OTHER TRANSMISSIONS ARE HORIZONTAL
Severity of disease and distribution - -ways to measure the impact of disease spread may only capture
those diseases that are apparent, and may underestimate the potential
Iceberg Concept -
Level of immunity - achieving high rates of immunity to a disease may alter disease spread in a
community
Herd immunity - the resistance of a group of people to an attack by a disease to which a large
proportion of the members of the group are immune
assumptions of herd immunity - -probability of an infected person encountering every other individual
in the population is the same (random mixing)
*some degree of variation for normal behavior still allows this assumption to hold true
Public Health - the science and art of preventing disease, prolonging life and promoting health through
organized efforts in society
Model for public health - -definition of the problem
-magnitude of the problem
-identification & understanding determinants
-develop medical or behavioral interventions/ prevention strategies (recommendation)
-set policy or public health priorities
-implement and evaluate
Surveillance - tracking of a disease
Epidemiology - the study of the distribution and determinants of health-related states or events in
specified populations and the application of this study to control health problems
Objectives of epidemiology - -identify the causes of disease (etiology)
-study of the natural history and prognosis
-determine the overall size of the problem in the community (prevalence) or measure how quickly it is
growing in the community (incidence)
Uses of Epidemiology evidence - 1. changing patterns of community health
2. developing and evaluating prevention programs
3. clinical practice
Changing patterns of disease - -epidemiologic shift
-infectious to chronic
,Prevention - -identification of high risk groups
*define how and why they are high-risk and potentially modify those factors before they acquire the
disease
*direct preventative measures to those high-risk groups most likely to benefit
types of prevention - *primary->prior to the disease occurring->vaccines
*secondary->early detection of existing disease to reduce severity and complications->screening, breast
exams
*tertiary->reducing impact of disease, no cure->rehab
Clinical practice - -the practice of medicine, although focused on one patient, is dependent of
population data
*diagnosis and screening
*prognosis
*selection of therapy
U.S. preventative task force - -recommendations on effectiveness of clinical preventative services for
those without symptoms
-recommendations based on evidence of both the benefits and harms and an assessment of balance
-recognizes clinical decisions involve more considerations than evidence alone
*clinicians should understand evidence but make decisions for the specific patient
*notes that policy and coverage decisions involve other considerations
Characteristics of epidemiology - -primarily a quantitative methodology that includes reasoning
-can be considered a basic science of public health
*biostats also shares these characteristics
What influences transmission? - 1. Interaction between host and agent, environment, and vector
2. mode of disease transmission
3. distribution of the severity of disease in the community
, 4. level of disease-to-immunity in the community
epidemiologic triad - interaction between host, agent, vector and the environment
modes of transmission - ways by which disease is passed within a community
Types of transmission - 1. direct-person to person contact
2. indirect-common vehicle, (single, multiple, continuous exposure), vector
Mode of transmission: Maternal to child - -vertical transmission of disease causing agents from mother
to child during:
*pregnancy, delivery or just after birth
*breastfeeding
*infections
-ALL OTHER TRANSMISSIONS ARE HORIZONTAL
Severity of disease and distribution - -ways to measure the impact of disease spread may only capture
those diseases that are apparent, and may underestimate the potential
Iceberg Concept -
Level of immunity - achieving high rates of immunity to a disease may alter disease spread in a
community
Herd immunity - the resistance of a group of people to an attack by a disease to which a large
proportion of the members of the group are immune
assumptions of herd immunity - -probability of an infected person encountering every other individual
in the population is the same (random mixing)
*some degree of variation for normal behavior still allows this assumption to hold true
