Epidemiology Flashcards
A state of complete physical, social, and mental well-being
Health
The presence of a condition that causes some level of dysfunction in the performance of the human body
Disease
The science of preventing disease, prolonging life, and promoting health and efficiency through organized community effort
Public health
The study of determinants, distribution, and frequency of health and disease in human populations
Epidemiology
True or false: diseases do not occur at random
True
Characterization of a disease pattern by demographic attributes
Descriptive EPI
-broad range of experiences
- can reveal similarities and differences across a range of populations
- expensive
- logistically challenging
Global
- provide results generalizable to country
- less genetic and cultural diversity than global
- can still be expensive and complete to conduct
National
- focus on a specific population of interest
- less expensive and logistically complicated
- lack ability to extrapolate to external populations
Regional
Population defined by non-place of residence characteristic
Special populations
What are the three factors of analytic epi triangle?
- Environment
- Host
- Agent
Characteristics that are specific to an individual
Host
Exposures that are necessary for the disease to occur
Agent
What are the 3 agent factors?
- Chemical
- Physical
- Biologic
Characteristics specific to the environment that surrounds an individual
Environment
What are the 3 external conditions for environmental factors?
- Physical
- Biologic
- Social
What are the 4 host factors?
- Personal traits
- Behaviors
- Genetic predisposition
- Immunological factors
To measure the relative amounts of health loss resulting from disease, injuries, and risk factors, with assessment of trends over time, place, and personal attributes
Global burden of disease
Changing patterns of population distributions in relation to changing patterns of mortality, fertility, life expectancy, and leading causes of death
Epidemiologic transition
What is the life expectancy and the fertility rate in a period of pestilence and famine?
Life expectancy low; high fertility
What is the primary cause of death in a period of pestilence and famine?
Infectious disease
What are the mortality rates for a period of pestilence and famine?
Mortality is high
When epidemics of plagues decrease
Period of receding pandemics
What is the primary cause of death in a period of receding pandemics?
Infectious disease
What happens to the mortality rate in period of receding pandemics?
Decreases
When do fertility rates decrease and the older population increases?
Period of degenerative and man made diseases
What is the primary cause of death in the period of degenerative and man made diseases?
Chronic disease
Where the mortality is concentrated at advanced ages
Period of delayed degenerative diseases and emerging diseases
What 3 things have lead to a dramatic decrease in infectious disease?
- Public health
- Medical treatment
- Sanitation
What is an urgent global public health threat?
Antimicrobial resistance
Type of population pyramid where both high fertility and high mortality rates are among younger members
Expansive
Type of population pyramid: low mortality and low fertility rates
Stationary
Type of population pyramid: lower mortality rate with the fertility rates remaining constant
Constrictive
Social standing or class of an individual or group. It is often measured by education, income, and occupation
Socioeconomic status
Surveillance in which either available data on reportable disease are used or reporting is mandated or requested
Passive
A system in which project staff make periodic field visits to health care facilities to identify new cases of disease or deaths from the diseases have occurred
Active
Which type of surveillance is more accurate and more complete?
Active
Which type of surveillance is less expensive and has a lack of completeness?
Passive
Form of surveillance undertaken to both understand the frequency of infectious diseases and to limit the spread of infectious diseases
Case surveillance
A file of data concerning all cases of a particular disease or other health-relevant condition in a defined population such that the cases can be related to a population base
Registry
A variety of surveys carried out by the government that are used to identify the frequency of disease and injury events
Population surveys
A form of surveillance that uses non traditional data sources to detect health events earlier than possible with traditional methods
Syndromic-surveillance
The factor that must be physically present for the disease to occur
Agent
No agent = no _______
Disease
What are 5 types of Biologic agents?
- Viruses
- Bacteria
- Fungal
- Prion
- Helminths
Ability to cause severe disease
Virulence
Place where the agent can live and grow
Source/ reservoir
Site from which the Biologic agent is transmitted
Source
The site where the Biologic agent grows and multiplies
Reservoir
True or false: agents can survive without a reservoir
False
How the agent exists the reservoir and enters the host
Portal of exit
How the agent is transmitted from the source to the susceptible host
Mode of transmission
Transmitted from person to person via direct close contact
Direct
What are the 2 types of direct transmission? What are examples?
- Vertical: mother to child
- Horizontal: between mucous membranes
What are the 2 types of indirect transmission?
- Fomite transmission
- Droplet transmission
Involves inanimate objects contaminated by an infected individual
Fomite transmission
Respiratory droplets which are propelled into the air by sneezing or coughing
Droplet transmission
The transfer of pathogens via very small particles and droplets that may remain suspended in the air for extended periods and be disseminated by air currents in a room or through a facility
Aerosol (airborne) transmission
Transmission of disease via food, water, drugs, blood products, and medical devices
Common vehicle transmission
An organism that can transmit infectious agents from one infected person or animal to another
Vector borne transmission
What are 5 types of portals of entry?
- Inhalation
- Absorption
- Ingestion
- Inoculation
- Introduction
Individual able to become infected
Susceptible host
Where transmission occurs but the number of cases remains constant. Constant low to moderate level of disease in a population
Endemic
Level of disease that exceeds the level that normally occurs, usually suddenly
Epidemic
Disease that does not largely exist in the population; occurs sporadically at low level with no pattern
Sporadic
Level in disease in a population is consistently high
Hyperendemic
Level of disease that exceeds the level that normally occurs , usually suddenly
Pandemic
What type of transmission are common source outbreaks usually caused by?
Indirect transmission
What type of common source outbreak implies that there is an ongoing source of contamination?
Continuous
What type of common source outbreak has a sharp rise in cases and a gradual fall. All exposures tend to occur in a relatively brief period?
Point source
Type of outbreak that usually lasts longer than common source
Propagated
True or false: propagated outbreaks have multiple sources of exposure
True
How are propagated outbreaks usually transmitted?
Person to person
True or false: correlation does not equal causation
True
What is assumed to exist until evidence exists to show otherwise?
Null hypothesis
Which type of error: identifying a relationship when in truth there is none
Type I
Type of error: failing to identify a relationship where there is one
Type II
How can type I and type II errors exist? 4
- Chance
- Random misclassification
- Bias
- Confounding
What are the 2 types of bias?
- Selection
- Information
Proportion of subjects misclassified in exposure is different in each outcome
Differential misclassification of exposure
Proportion of subjects misclassified on outcome is different in each outcome group
Differential misclassification of outcome
Proportion of subjects misclassified on exposure is same in each outcome group
Non differential misclassification of exposure
Proportion of subjects misclassified on outcome is same in each outcome group
Non differential misclassification of outcome
Occurs when study participants do not accurately or completely recall prior events of experiences
Recall bias
Occurs when study participants purposely suppress or reveal information on a study variable because of social stigma
Reporting bias
Occurs when an interviewer solicits or interprets information differently between study subjects
Interviewer bias
Occurs when study personnel observe information differently from the study participants
Observer bias
Difference in diagnosis or ascertainment of study measures over time between study participants
Detection bias
Difference where one study group is followed more closely than the other; outcome identifies more frequently in closely followed group
Surveillance bias
Error in study result due to the selection of participants
Selection bias
May exist in any study design that relies on individuals to agree to participate in the study
Self selection/ non response bias
When the control group selected is not representative of the population that produced the cases
Control selection bias
Occurs in longitudinal studies when differential loss to follow up exists
Loss to follow up bias
Occurs because the exposure values in hospitalized subjects particularly controls may not be the same as exposure values for the source population
Berksons bias
What is the healthy worker effect? 2
1.person may be selected for employment based on good health
2. The person who continued to work may be selected to continue use based on good health
A group in a targeted population has enhanced survival effect and thus their participation is related to the exposure, outcome, and/or confounding variable
Survivor effect
If a factor is believed to be the cause of a disease, exposure to the factor must have occurred before the disease developed
Temporal relationship
True or false: the strength of association is measured by absolute risk
False (relative risk)
The stronger the association, the more likely it is that the relation is _____
Causal
As the dose of the exposure increases, the risk of disease _______. What is this called?
Increases; dose response relationship
Component that causes the disease from the effect of another factor
Mediators
A component that affects the strength or direction of the association between the factor and the disease
Moderator