Final Exam Cumulative Flashcards
What is Epidemiology?
The study of diseases through data, focusing on populations and demographics.
Chronic
Disease that progresses slowly but lasts a long period of time.
Acute
Disease that is sever and happens quickly but lasts only a short time.
Outbreak
Infectious disease that affects many people over time.
Epidemic
Disease that spread over a large population.
Endemic
Disease that persists in a population over lengthy period of time.
Pandemic
Disease that spreads over a larger population (globally).
Father of Epidemiology who used natural experiments.
John Snow
Members of a population who are capable of developing a disease/condition.
Population at risk.
Number of years a person is expected to live at any particular year.
Life expectancy.
when the duration of a disease becomes short, incidence increases and so does ____.
Prevalence
Prevalence
The frequency of existing cases.
Incidence
The frequency of new cases.
Morbidity
Those who are sick/infected with disease.
Mortality
Those who are dead.
Difference between Clinical Medicine to Epidemiology?
Clinical focuses on the individual while Epidemiology focuses on the population.
(Quantification) Primary Prevention
Example- Eating Healthy, exercising, etc.
(Quantification) Secondary Prevention
Example- Screenings, examinations, Catching it before it’s there.
(Quantification) Tertiary Prevention
Example- Treatment, chemotherapy, etc.
Descriptive Epidemiology
Characterized by the amount and distribution of a disease in a population.
Analytic Epidemiology
Examines etiological hypotheses regarding the association between exposures and health outcomes.
This rate does not permit comparisons of populations that vary in composition.
Crude Rates
True or False: Tetanus, Rubella, and Measles are all Notifiable Diseases.
True
The top of the Asthma Prevention pyramid is?
Mortality
A centralized Data Base for the collection of information about diseases, such as cancer is known as_______.
Case Registry .
The systematic and continuous gathering of information about the occurrence of diseases and other health phenomena
Public Health Surveillance.
Classical Antiquity
Before 500AD
Hippocrates
Suggested diseases must be associated with environmental factors rather than superstitious reasons.
Middle Ages
Black Death- Swollen lymph nodes, Fever, Black spots on skin.
Paracelsus (Renaissance)
One of the founders of Toxicology Field.
Most associated with Dose-response relationship
Target Organ specificity of chemicals.
John Graunt (Renaissance)
first to Employ quantitative Methods
Known as the Columbus of statistics.
Ramazzini
18th c.
Founder of the field of Occupational Medicine
Sir Percival Pott
18th c.
first person to describe an environmental cause of cancer.
(Chimney sweeps, had a high incidence of scrotal cancer.)
Edward Jenner
18th c.
developed method for smallpox vaccine.
John Snow
19th c.
Believed that cholera was transmitted through contamination and proved the association.
John Snow’s Experiment
Used a spot map to identify cases.
Used Data tables to describe infectious disease.
Recommended public Health Measure to prevent disease.
Miasmatic theory
Diseases transported to people by miasma or a cloud that clung low to the surface of the earth.
William Farr
19th c.
Developed more sophisticated way of codifying medical conditions.
Examined linkage between mortality rates and population density.
Robert Koch
19th c.
Association between microorganism and diseases
Kochs postulates
1.Must be observed in every case.
2.must be isolated and grown in culture.
3.The pure culture must be put into an animal and reproduce the disease.
4.Organism must be observed in and recovered from the animal.
Pandemic Influenza
Early 20th c.
Spanish flu
1/3 of world’s population became infected.
killed 50-100 million people globally
Alex Fleming
20th c.
Discovered Penicillin
Three types of Presentation of Data (Graphical)
Bar chart
Line chart
Pie chart
Type of graph that shows the frequency of cases for categories of categorical (discrete) variables such as Yes/No variable.
(Includes histogram)
Continuous, infinite numbers
EX weight, height, blood sugar levels
Bar Chart
Displays trends
Example Time Trends
Line Graph
Circle that shows proportion of cases according to serval categories.
Pie Chart
R=(x/y)
Rates
Proportions
Percentages
Ratio
p= A/(A+b)
Proportion
P=A/(A+B)x100
Percentage
r= x/(time)
# of health events/population in which event occurs.
Rate
Number of new cases/number of individuals in population cases at risks x100,000
Incidence Rate
Number of new cases/Total population at risk during same time period
Cumulative Incidence
Number of people ill at point in time/total number in group
Point Prevalence
All cases of a disease within a period of time
Period prevalence
Cases diagnosed at any time period of persons lifetime.
Life prevalence
What happens to Prevalence if:
Increase of incidence
longer duration of the case
in-migration of cases
Prolongation of life of patients without cure
Increased prevalence
What happens to Prevalence if:
Decrease in Incidence
Shorter duration of disease
in-migrant of healthy people
improved cure rate of disease
Decreased Prevalence
Most common method of disease transmission in urban areas
Person to Person Contact
True or False: People can be characterized into a race based on physical characteristics.
False
______ the generalizability of the findings the population from which data has been taken.
External Validity
Conducted every 10 years.
Provides data that can be used to define the denominator in rates with respect to official estimates of total population size and subdivisions of the population by geographical area.
US Bureau of Census
Vital Events
Deaths, births, deaths, marriages divorces, and fetal deaths.
Compiles and publishes national mortality rates.
National Center for Health Statistics (NCHS)
True or False: Mortality data is almost totally complete.
True, death does not go unrecorded.
True or False: Specificity of cause of death is entirely accurate.
False
What are these all apart of?
Communicable and infectious diseases
non-infectious diseases
Risk factors for chronic diseases
Public health surveillance programs
Used to monitor at state levels behavioral risk factors that are associated with chronic illness.
Gather data related to health risk factors, preventative health practices, and healthcare access.
Behavioral Risk Factor Surveillance System (BRFSS)
National program of Cancer Registries (NPCR) and The Surveillance, Epidemiology, and End Results (SEER) are all apart of what?
Case Registries
National Health interview survey
National health and nutrition examination survey (NHANES)
The Vital Statistics system
National Center for health Statistics (NCHS)
Which program conducts the National Health interview Survey?
National Center for Health Statistics (NCHS)
Which program is used to track the people’s health status and access to health care?
National Health interview Survey (NHIS)
Which Program collects data from physicians such as weight, height, and so forth?
National Health and Nutrition Examination Survey (NHANES)
True or False: The World Health Organization (WHO) and the European Union provide international and foreign data regarding disease and health.
True
A Rate that has not been modified to take into account of any of the factors, such as the demographic makeup of the population that may affect the observed rate.
Crude Rate
A type of Crude rate
Number of deaths in given year/ Reference population x 100,000
Crude Death Rate
Number of deaths due to a disease that occur amongst persons who are afflicted with that disease.
Number of deaths due to disease/number of cases of disease x 100
Case Fatality Rate (CFR)
The number of deaths within a population due to a specific disease or cause divided by the total number of deaths in population.
Deaths due to specific disease during time period/number of all deaths during time period x 100
Proportional Mortality Ratio (PMR)
A measure that refers to mortality (or frequency of a given disease) divided by the population size at the midpoint of a time period times a multiplier.
Mortality/frequency of disease/Population size at midpoint time period x100,000
Cause-Specific Rate
Number of deaths among those age 15-24/number of persons aged (15-24) in time period x 100,000
Age specific Rate
Number of sex specific deaths/number of sex specific in population of time period x 100,000
Sex Specific Rate
True or False: Age is a rate used in rate adjustment.
True
Maternal deaths that result from causes associated with pregnancy.
Number of deaths related to childbirth/number of live births x 100,000
Maternal Mortality Rate
number of infants (under 1 yr) deaths during the year/number of live births during the year x100,000
Infant Mortality Rate
Two measures of Fetal Mortality
Fetal Death Rate
Late Fetal Death Rate
Number of fetal deaths after 20 weeks or more gestation/number of live births + number of fetal deaths after 20 weeks or more gestation x 1,000
Fetal Death Rate
Number of fetal deaths after 28 weeks or more gestation/ number of live births + number of fetal deaths after 28 weeks or more gestation x 1,000
Late Fetal Death Rate
Number of babies born/total population x 1,000
Crude Birth Rate
Number of live births within a year/ number of women aged 15-44 x 1,000
General fertility rate
True or False: Pernatal mortality does not include both late fetal deaths and deaths among newborns.
False. Pernatal does include late Fetal deaths and deaths among newborns.
Number of late fetal deaths (28) + infant deaths within 7 days of birth/ Number of live births +number of late fetal deaths x 1,000
Pernatal Mortality Rate
Accounts of single occurrence of a noteworthy health related incident or of a small collection of such events
Case Report
Larger collection of cases of diseases, often grouped consecutively and listing common features such as characteristics of affected patients.
Case Series
Type of investigation that examines the relationship between disease and other variables of interest as they exists in a defined population or at particular time.
Type of prevalence study
BRFSS
Cross-sectional Study
Three types of Descriptive Epidemiological study designs
Case Report
Case Series
Cross-sectional study
Descriptive term for a persons position in society
Often formulated by- a persons income level, education level, and type of occupation.
Socioeconomic Status (SES)
True or False: Those in the lowest SES positions are confronted with excess of morbidity and mortality from numerous causes.
True
Person Variables
Sex
Age
race/ethnicity
nativity
socioeconomic status
marital status
migration
religion
Place Variables
International
national (within country)
Urban-rural differences
Localized patterns of disease
Time Variables
Secular
Cyclical(seasonal) trends
Point epidemics
Clustering
______ Clustering, refers to aggregation of events in geographic region.
Spatial
_____ Clustering, Denotes the occurrence of events related to time.
Temporal
Hypothesis
H0:U=X
Null Hypothesis
Hypothesis
H0:U>X
Alternative Hypothesis
Central concern of epidemiology
Ability to assert that a causal association exist between an exposure factor and disease outcome.
Several criteria must be satisfied in order to be satisfied to assert that a causal association exists.
Causality
Hill’s Causal Criteria (SCSTBCA)
1.Strength (strong association between factor and disease)
2.Consistency (association must be observed repeatedly)
3.Specificity (Association is constrained to a particular disease-exposure)
4. Temporality (the cause must be observed before the effect)
5.Biological gradient (dose-response curve; shows linear trend association between exposure and disease.)
6.Coherence (Cause and effect interpretation of data should not conflict generally known facts of natural history and biology of the disease.)
7.Analogy (Relates to correspondence between known association and one that is being evaluated for causality)
More than one causal factor
Multifactorial Causality
The value for population is referred to as a parameter, and the corresponding value for the sample is statistic.
A single value (sample based) chosen to represent the population.
Point Estimate
Range of values that within a certain degree of probability contain the population parameter.
Alternative to point estimate
Confidence interval
Analytical Study design for Epidemiology
Case-control
Cohort
Ecological
Experimental
Two categories of analytic studies
Observational (ecologic, case control, cohort)
Experimental
Units of analysis are populations or groups not individuals
Ecological studies
Involves an assessment of the association between exposure rates and disease rates during the same time period
Ecologic Comparison Study
An association between two variables (exposure and Outcome) measured at the group level
Ecologic Correlation
An erroneous inference that may occur because an association observed between variables on an aggregate level does not necessarily represent or reflect the association that exists at an individual level.
Ecologic Fallacy
Subjects are defined as having or not having disease.
Cases are individuals who have the outcome or disease, Controls do not.
Case-control
Cases and controls have been matched according to one or more criteria such as sex, age, race, or other variables
Matched case-control Study
(AD/BC)
Odds Ratio
Odds Ratio belongs to ______.
Case-Control
If OR > 1
Suggests a positive association between exposure and disease
If OR = 2
Suggests the odds of disease are about two times higher among the exposed than among the unexposed.
If OR < 1
Indicates that the exposure might be a protective factor.
If OR = 1
Indicates no association.
Advantages
Used for low prevalence conditions
quick and easy to complete
inexpensive
smaller subjects
Case-control
Disadvantages
Measure of exposure may be inaccurate.
Representativeness of cases and control may be unknown.
provide indirect estimates of risk.
Case Control
A population group, distinguished by a common characteristic, that is followed over a period of time
Cohort
Subjects classified according to exposure to a factor of interest, then observed over a period of time to document the occurance of new cases
Prospective Cohort Study
Historical data to determine exposure level in past.
Follow-up for subsequent occurrence of diseases between baseline and present is performed.
Retrospective Cohort Study
Relative Risk belongs to ________.
Cohort Study
Incidence rate in the exposed/incidence rate in the unexposed
Relative Risk
Incidence of disease in exposed group
A/(A+B)
Incidence of disease in non exposed group
C/(C+D)
Relative Risk (RR)
(RR)= [A/(A+B)]/[C/(C+D)]
Advantages
Permits direct observation of risk.
Exposure factor is well defined.
Can study exposures that are uncommon in the population.
Temporal Relationship between factor and outcome is known.
Cohort
Disadvantages
Expensive and time consuming.
Complicated and difficult to carry out.
Subjects may be lost to follow up during course of study.
Exposure can be misclassified.
Cohort
Randomized Control Trial (RCT)
Quasi-experimental design are what.
Experimental studies
Subjects in a population are randomly allocated into groups, usually called study and control groups, to receive (study group) or not to receive (control group) an experimental intervention.
Randomized Controlled Trial
Investigator manipulates the study factor but does not assign individual subjects randomly to the exposed and unexposed groups.
Quasi Experimental
Ability to generalize from the results of the study to an external population.
Convenience sample may not demonstrate external validity.
Random samples are more likely to demonstrate external validity than convenience samples.
External Validity
Arise when values (stats) obtained for a sample differ from the values (Parameters) of the parent population
Sampling error
Refers to the degree to which the study has used methodologically sound procedures
Internal Validity
Participants behavioral changes as a result to them knowing they’re in a study.
Hawthorn Effect
Cases may remember an exposure more clearly than control
Recall Bais
Distortions that result from procedures used to select subjects and form factors that influence participation in the study
Selection Bias
Distortion of a measure of the effect of an exposure due to association of of exposure with other factors that may influence the occurrence of the outcome
Confounding Bias
Disease due to an infectious agent
Infectious disease
This person completes and signs the death certificate if the cause of death was an accident, suicide, or homicide, or if the attending physician is unavailable
Medical Examiner or Coroner
True or False: Information on death certificates regarding cause of death is always correct.
False
True or False: Infant mortality rates are lower in upper social classes as compared to lower social classes.
True
This document contains these three pieces of information: Name, disposition, and congenital abnormalities.
Fetal death certificate
Document used to study the effect of exposure to teratogens
Birth certificates
This rate encompasses maternal deaths that result from causes associated with pregnancy
Maternal Death Rate
In hills Criteria of temporality, Epidemiologists need to observe the ____ before the _____.
Cause and effect.
The ____ __ ____ model specifies a type of causal relationship is multifactorial.
Web of Causation
True or False: one to one causation is common because most disease have just one causal factor
False
A ____ cause is sufficient by itself to produce the effect.
Sufficient
True or False: Ecological studies use the individual, rather than the group, as the unit of analysis
False
True or False: A case control study can examine only a single outcome or limited set of outcomes
True
In a ____ design, participants may be switched among the treatment.
Crossover
An ____ study is one that examines a group as a unit of analysis
Ecological
This is an inanimate object that carries infectious Disease agents
Fomite
This is an animate, living insect or animal that is involved with the transmission of disease agents.
Vector
The likely transmission of SARS during a 2003 flight to Beijing is thought to have been transmitted how
Airborne
three modes of transmission for human immunodeficiency virus (HIV)
Unprotected intercourse
contact with infected blood
transmission from infected mother to child.
The ability of a study to demonstrate an association if one exists is known as:
Power
Association between the number of cigarettes smoked and the rate of lung cancer deaths is an example of what type of gradient?
Biological gradient
In Case Control Studies, a type of indirect measure of the association between frequency of exposure and frequency of outcome is known as what?
Odds Ratio
The Ratio of the incidence rate of a disease in an exposed group to the incidence rate of the disease in an non exposed group is called:
Relative Risk
_____ That persists in the environment have been associated with the disruption of the immune system, reproductive system, and nervous system.
Toxic Chemicals
How can food borne illness be prevented
Washing Hands, surfaces, where food is prepared. (NOT eating home canned food or storing food at room temperature)
______ is the leading cause of cancer death for both men and women In the US.
Lung Cancer
Three Adverse health outcomes associated with cigarette smoking
Stroke,
lung disease,
coronary heart disease
Infection caused by parasite, organisms that lives in or in hot and gets food from or at the expense of host
Parasitic Disease
One of the long standing models used to describe the etiology of infectious diseases.
Three major factors: Agent, host and environment
Epidemiological triangle
A factor such as a microorganism, chemical substance, or form of radiation- whose presence, excessive presence, or (in deficiency disease) relative absence is essential for the occurrence of a disease.
Agent
The Domain in which disease causing agents may exist, survive,or originate
Environment
A Person or other living animal, including birds and arthropods, that affords subsistence or lodgment to an infectious agent under natural conditions.
Host
Capacity of an ant to enter and multiply in a susceptible host and thus produce infection or disease
Infectivity
Severity of there disease produced whether the disease has severe clinical manifestation or is fatal in large numbers.
Virulence
True or False: Some infectious disease agents instead of acting directly, create a toxin that causes illness
True
Host’s ability to resist infection by agent
Immunity
____ develops as a result of natural infection with microbial agent, can also be acquired from injection of vaccine that contains an antigen, and usually measured in years.
Active Immunity
Acquired from antibodies produced by another person or animal, usually of short duration. Example-newborns immunity conferred transplacentally from mother
Passive immunity
The resistance of an entire community to an infectious agent as a result of the immunity of a larger proportion of individuals in that community to the agent
Herd Immunity
Time interval between invasion by agent and the appearance of the first sign or symptom
Incubation Period
An infection that does not show obvious clinical signs of symptoms
Subclinical illness (inapparent infection)
Time interval between lodgment of an agent in a host and maximal communicability of host
Generation Time
Person or animal that harbors a specific infectious agent without discernible clinical disease, and serves as a potential source of infection
Carrier
Used in epidemiological investigation of disease outbreak to denote the first case of a disease to come to the attention of authorities
Index Case
A Place where infectious agents normally live and multiply. Can be human beings, animals, insects, soils, or plants
Reservoir
An infection or infectious agent transmissible under natural conditions from vertebrate animals to humans example rabies
Zoonosis
Two types of Transmission
Direct and indirect Transmission
Direct transmission that essentially immediately transfer of infectious agent to a receptive portal of entry through which humans or animals infection may take place
Person to Person
_______ involves intermediary sources of infection such as vehicles, droplet nuclei (particles), and vectors
Indirect transmission.
3 types of Indirect transmission
Vehicle borne infections
Airborne infections
Vector born Infections
Site where the agent enters the body
example skin wound
Portal of Entry
Site from which the agent leaves infected person’s body
Example- respirate passages, skin lesions
Portal of exit
Fomite
Indirect transmission of inanimate object
Involves the spread of droplet nuclei (Particles) present in the air
Airborne Infection
An animate, living insect or animal involved with disease agents transmission
Vector Borne
An infectious disease that has newly appeared in a population or that has been known for some time but is rapidly increasing in incidence or geographic range
Emerging Infectious diseases
Methods of Outbreak (DAFCD)
1.Define the problem
2.Appraise the data
3.Formulate the hypothesis
4.Confirm the hypothesis
5.Draw a conclusion and formulate practical application
The pattern of symptoms that suggest possible infectious agent
Clinical Observation
(diarrhea Fever, vomiting, rashes etc)
A graphic plotting of distribution of cases by time of onset
Epidemic Curve
(Epidemic Curve) Due to exposed of a group of persons to a noxious influence that is common to the individuals in the group
Common Source Epidemic Curve
(Epidemic Curve) Occurs when the exposure is brief and essentially simulates, the resultant cases all develop within one incubation period of the disease
Point Source Epidemic Curve
Used frequently to describe the occurrence of food borne illness, infectious diseases, and other accurate epidemics
Attack Rate
ILL/(ILL+well)x100
Attack rate formula
Case Mapping
Hypothesis
Drawing conclusions
Final Steps in Outbreak investigation
True or False: a necessary cause is sufficient by itself to produce the effect
False
the existence of dose-response relationship, that is, an increase in disease risk with an increase in the amount of exposure, supports amount of exposure, supports the view that an association is ______ one.
Causal
True or False: The overriding question that epidemiologists ask is whether a particular exposure is casually associated with a given outcome
True
True or False: John Snow determined that the 1880 cholera epidemic was caused by a poisonous vapor or “Miasma Theory”
False, He challenged the miasma theory
This type of study is a good approach for generating hypothesis
Ecological studies
_____ studies are the best observational study designs to study decrease of low prevalence
Case Control
Name the Study type:
A population of a given community is examined. All who are judged to be free from bowel cancer are questioned about their diets. They are then followed for several years to see whether there eating habits will predict their risk of developing bowel Cancer.
Prospective Cohort
True or False: Exposure based cohort studies permit investigation of exposures that are uncommon
True
True or False: Rabies and Anthrax are zoonotic diseases
True
A ____ is a human, animal, insect, soil/or plants that harbor disease
Reservoir
_____ is the severity or harmfulness of a disease
Virulence
True or False: Droplet nuclei can be involved in indirect transmission of disease
True Airborne transmission
severe tooth decay and loss of teeth occur most commonly among people who use this drug.
Methamphetamine
Alcohol consumption by underage persons is associated with what consequence
Problems at school
Health problems associated with binge drinking among college students (3)
Violence
sexually transmitted diseases
Unintentional injuries
_______ is the involuntary breathing of cigarette smoke by nonsmokers in an environment where there are cigarette smokers present
Passive smoking
Second hand exposure
Environmental tobacco smoke exposure
The Co-occurrence of two or more mental disorders is known as _______ ________
Psychiatric comorbidity
_____ _______ ________ is an anxiety disorder that some people develop after seeing or living through an event that caused or threatened serious harm or death is known as.
Post-traumatic stress disorder
True or False: stressful life events can be classified as either positive or negative
true
Post traumatic stress disorder among which population is linked with increased levels of health problems and healthcare utilization
Veterans
Sub discipline of epidemiology focusing on the social distribution and social determinants of states health
Social Epidemiology
The study of the role of behavioral factors in health
Behavioral Epidemiology
A physical, chemical, or emotional factor that causes bodily or mental tension and may be a factor in disease causation.
Stress
Outcomes of stress
Cardiovascular disease
Post traumatic Stress disorder
Work related anxiety and neurotic disorders
Life events that are sustained over a long period of time
Chronic Strains
Symptoms of PTSD
Flachbacks
Angry outbursts
Emotional numbness
Intense guilt or worry
Two forms of dealing with stress
Social Support
Coping skills
True or False: Secondhand smoke exposure causes diseases and premature death in children and in adults who do not smoke
True
Manual used for the classification of psychiatric disorders (DSM)
Diagnostic and statistical manual of mental disorders, 5th generation
Condition that impairs functioning In the social, communication, and behavioral domains
Autism
