Epidemiology Ch. 1
Terms in this set (327)
the occurrence in a community or region of cases of an illness, specific health-related behavior, or other health related events clearly in excess of normal expectancy
Can one or two cases of a disease be an epidemic?
Yes, if the disease normally does not occur at all in that area; ex. if measles was to occur in the U.S.
an epidemic occurring worldwide, or over a very wide area, crossing international boundaries, and usually affecting a large number of people
What is a special concern of the field of epidemiology?
a field concerned with the distribution and determinants of health and diseases, morbidity, injuries, disability, and mortality in populations. Epidemiologic studies are applied to the control of health problems in populations
all the inhabitants of a given country or area considered together
Why is epidemiology sometimes referred to as population medicine?
because it's concerned with the population rather than the individual
the disbursement of disease and health outcomes; implies that the occurrence of disease and health outcomes varies in populations with some subgroups of the population more frequently affected than others
any factor that brings about change in a health condition or other defined characteristic
ex. bacteria, viruses, pesticides, stress, poor lifestyle choices
pertain either to contact with a disease-causing factor or to the amount of the factor that impinges upon a group or individuals
Epidemiology searches for associations between........?
exposures and health outcomes
all the possible results that may stem from exposure to a causal factor
illnesses due to a specific disease or health condition
cause of death
counting of cases of illness or other health outcomes;
Quantification means the use of statistical measures to describe the occurrence of health outcomes as well as to measure their association with exposures.
Is epidemiology a quantitative or qualitative field?
quantitative; it uses statistics
natural history of disease
the course of disease from its beginning to its final clinical endpoints
period of prepathogenesis
the time period in the natural history of disease before a disease agent (e.g., a bacterium) has interacted with a host (the person who develops the disease).
period of pathogenesis
the period after the agent has interacted with the host
What are the three types of prevention of disease?
primary, secondary, and tertiary
the prevention of disease before it occurs; primary prevention targets the stage of prepathogenesis and embodies general health promotion and specific prevention against diseases.
Ex. vaccines, health education programs
takes place during the early phases of pathogenesis and includes activities that limit the progression of disease.
Ex. cancer screenings to help catch cancer early before it gets severe
directed toward the later stages of pathogenesis and includes programs for restoring the patient's optimal functioning
Ex. physical therapy for stroke victims or fitness programs for recovering heart attack patients
a science that uses information from many fields
Ex. Epidemiology is an interdisciplinary science
a science that capitalizes on naturally occurring situations in order to study the occurrence of disease
Ex. epidemiologists might look at the frequency of lung cancer in smokers and nonsmokers
epidemiologic studies that are concerned with characterizing the amount and distribution of health and disease within a population
classifies the occurence of disease according to person, place, and time
What is a descriptive epidemiology study concerned with?
concerned with characterizing the amount and distribution of disease within a population
What is the aim of descriptive studies?
Descriptive studies aim to delineate the patterns and manner in which disease occurs in populations. These studies, which are focused on the development of hypotheses, set the stage for subsequent research that examines the etiology of disease.
According to what three variables are health outcomes classified?
person, place, and time variables
race, ethnicity, sex, age
denote the location of disease, ex. country or state
year, month, week, day
examines causal (etiologic) hypotheses regarding the association between exposures and health conditions
causal studies; aim to find the cause of a disease;
planned examinations of causality and the natural history of disease.
naturally occurring circumstances in which subsets of the population have different levels of exposure to a supposed causal factor in a situation resembling an actual experiment, where human subjects would be randomly allocated to groups
suggested that environmental factors such as air and water quality could contribute to disease
epidemic of the bubonic plague; claimed close to a third of the european population; can be transmitted by flees and rats
Who is known as the founder of toxicology?
Paracelsus; came up with dose response relationship and target organ specificity of chemicals
dose response relationship
discovered by Paracelsus; observation that the effects of a poison are related to the strength of the dose
a discipline that is used to examine the toxic effects of chemicals found in environmental venues such as the workplace
Who is known as the Columbus of Statistics?
Graunt; made mortality statistics and birth statistics; created a mortality table; first to use mortality statistics
Who is regarded as the founder of of occupational medicine?
Ramazzini; looked at risks posed in the workforce of various jobs; also looked at danger of certain postures at work; also founder of ergonomics; looked at occupational diseases caused by chemicals, dusts, and metals used in the workforce
study of people's efficiency in their working environment
Sir Percival Pott
surgeon that is thought to be the first to find an environmental cause for cancer; noticed higher incidence of scrotum cancer in chimney sweepers; recommended hygiene protocol
came up with a vaccine for smallpox using cowpox virus which was not as dangerous and easily fought off; used material from a dairymade with an active case of cowpox and injected the material into an 8 year old boy who later was exposed to smallpox and didn't develop the disease
Dutchman Anton van Leeuwenhoek
used microscopes to observe micro-organisms (bacteria and yeast) but did not find an association with disease
miasmatic theory of disease
disease was transmitted by a miasm, or cloud, that clung low on the surface of the earth
made association of infected water with cholera outbreak by plotting deaths around water pumps; found that the Lambeth company water pump was cleaner because of lower mortality rates; found that if high level exposures weren't affecting people low level environmental exposures shouldn't be dangerous
developed a more sophisticated system for coding medical conditions
verified that disease was caused by a specific living organism; isolated the bacteria that caused cholera and anthrax; also identified the cause of tuberculosis
Pandemic influenza (Spanish Flu)
affected one third of the world population; affected healthy young adults; thought to interact with respiratory bacteria making people sick
discovered penicillin from a mold
looked at the etiology of certain diseases such as coronary heart disease
hired by the CDC to help counter bioterrorism; helped establish EIS
published 7 uses of epidemiology;
Historical use: study the history of the health of populations
• Community health use: diagnose the health of the community
• Health services use: study the working of health services • Risk assessment use: estimate individuals' risks of dis¬ ease, accident, or defect
• Disease causality use: search for the causes of health and disease
describes a shift in the patterns of morbidity and mortality from causes related primarily to infectious and communicable diseases to causes associated with chronic, degenerative diseases
a shift from high birth rates and death rates found in agrarian societies to much lower birth and death rates in developed countries
community health use
described by Morris as the ability to diagnose the health of the community and the condition of the people, to measure the true dimensions and distribution of ill-health in terms of incidence, prevalence, disability and mortality; to set health problems in perspective and define their relative importance; to identify groups needing special attention
Ex. age and sex distributions, racial/ethnic makeup, socioeconomic status, employment and unemployment rates
a type of study of the placement of health services in a community and the optimum utilization of such services
a method of reducing healthcare costs by providing integrated care for chronic conditions, e.g., heart disease, hypertension, and diabetes
the probability that an event will occur, e.g., that an individual will become ill or die within a stated period of time or by a certain age
an exposure that is associated with a disease, morbidity, mortality, or adverse health outcome
Ex. smoking increases risk of cancer
quantitative measurements of risk
norms for conduct that distinguish between acceptable and unacceptable behavior
American College of Epidemiology Ethics Guidelines
1. Minimizing risks and protecting the welfare of research subjects
2. Obtaining the informed consent of participants
3. Submitting proposed studies for ethical review
4. Maintaining public trust
5. Meeting obligations to communities
reviewing a data set for accuracy and completeness
What happens after data cleaning?
counting and tabulating cases
What happens after counting and tabulating cases?
plotting the data in a graph
a variable that has a fixed number of categories; ex. exposed and unexposed groups
a variable that could represent any amount between the end points; ex. if a fire department said that in order to join you have to weigh between 150 and 200 pounds the person could weigh anything between that amount
a variable that has set amounts; ex. when flipping a coin you can only get integer numbers of heads or tails - you can't get 2.5 heads
What are the three epidemiologic measures?
1. the frequency of disease or condition
2. association between exposure and health outcome
3. strength of the relationship between the exposure and health outcome
the value obtained by dividing one quantity by another
example of ratios
rate, proportion, and percentage
a type of ratio where the numerator is part of the denominator - may be expressed as a percentage
a proportion that has been multiplied by 100
Ex. A/(A+B) * 100
a proportion in which the denominator involves a unit of time
the number of cases of disease being studied
refers to the new occurence of a disease in a specified time such as in a specified year
population at risk
people in a population capable of getting the disease being studied
the number of new cases of a disease divided by the population at risk in a given time period
the number of existing cases of a disease at a specific time
the number of people with a disease divided by the number of people in a population at a given point in time; not a rate- only a proportion
the number of people with a disease divided by the number of people in a population over a certain period of time; ex from the year 2000-2010
cases of disease diagnosed at any point within someone's lifetime
Would a disease with a long duration or a short duration be more prevalent assuming incidence rates were the same?
a type of rate that has not been modified to take account of any of the factors such as the demographic makeup of the population that may affect the observed rate; includes a time period
Ex. crude death rate
the population from which cases of disease were taken; ex. the total population might be counted from the midpoint of the year
case fatality rate
number of deaths due to a disease that occur among people afflicted with the disease
expressed as number of deaths due to particular disease divided by number of people with disease *100 expressed as a percentage
proportional mortality ratio
deaths within a population due to a specific disease divided by the total number of deaths in a population - usually expressed as a percentage
cause specific rate
mortality (or frequency of disease) divided by population size at midpoint of time period
age specific rate
number of cases of disease per age group during a specific period of time
Ex. Number of people 18-24 with asthma divided by number of people age 18-24
sex specific rate
number of people in a given gender group with a disease divided by the number of people of that gender
age adjusted death rates
shows what the level of mortality would be if age was not a factor
What are two vital concerns of epidemiology?
1. the quality of data available for describing the health of populations
2. the appropriate applications of these data
representativeness (external validity)
the extent to which the results of the study can be generalized to other situations
U.S. Bureau of the Census
gives estimates on population size and subpopulations - conducts a census every 10 years
What are vital events?
deaths, births, marriages, divorces, and fetal deaths
Who collects information on vital events?
the vital registration system which then sends the information to the National Center for Health Statistics (NCHS)
public health surveillance
the systematic and continuous gathering of information about the occurence of disease and other health phenomenon
surveillance that uses health related data to signal the probability of a disease outbreak warranting public health response
Where does the CDC report quarantinable diseases to?
the World Health Organization
state level surveillance system
a centralized database for collection of information about a disease
the document used to collect the information about a disease
the number of years that a person is expected to live at any particular year
maternal deaths from causes associated with pregnancy divided by the number of live births in a specified time period
infant mortality rate
number of infant deaths (age 0 to 365 days) divided by the number of live births in a specified time period
fetal death rate
number of fetal deaths after 20 weeks or more of gestation divided by the number of live births and number of fetal deaths after 20 weeks gestation during a specified time period
late fetal death rate
number of fetal deaths after 28 weeks or more of gestation divided by the number of live births and number of fetal deaths after 28 weeks gestation during a specified time period
crude birth rate
number of live births divided by the population size in the middle of a specified time period
general fertility rate
number of live births divided by the number of women age 15-44 years at the midpoint of the year
perinatal mortality rate
number of late fetal deaths after 28 weeks gestation plus infant deaths within 7 days of birth divided by number of live births plus number of late fetal deaths
Descriptive epidemiologic studies classify diseases in terms of what three variables?
person, place, and time
What is a descriptive epidemiologic study concerned with?
concerned with characterizing the amount and distribution of health and disease within a population
account of a single occurence of a noteworthy health related incident or small collection of such events
a larger group of case reports
cross sectional study
a type of prevalence study that analyses data taken from a population at a specific point in time
Ex. how much sleep did you get over the last 30 days? looking at prevalence of insomnia
place of origin of the individual or his relatives
differences in the occurence of diseases and adverse health conditions in a population
socioeconomic status (SES)
a persons position in society; usually based off of income level, education, and type of occupation
gradual changes in diseases over long time periods
increases or decreases in disease over a year or several years
the response of a group of people circumscribed in place to a common source of infection, contamination, or other etiologic factor to which they were exposed almost simultaneously
a closely grouped series of events or cases of disease with well defined distribution patterns in relation to time or place or both
usually describes aggregation of uncommon diseases such as leukemia
disease clustering that occurs in a specific geographic region
Ex. certain types of cancer
disease clustering that occurs during a specified time period
Ex. postpartum depression
any quantity that varies. Any attribute, phenomenon, or event that can have different values
the linkage between variables - positive or negative associations
as one variable increases the other increases
as one variable increases the other decreases
The closer the correlation is to 1 the stronger...
the positive association
The closer the correlation to -1 the stronger....
the negative association
An r value near 0 means....
dose response curve
an association between an exposure and outcome that has a higher effect with a higher dosage
the point in a dose response curve at which a particular response occurs
What happens when the maximum response is reached in a dose response curve?
the curve flattens out
a curve that has several peaks in the frequency of a condition
the category in a frequency distribution that has the highest frequency of cases - there can be more than one mode
the time period between initial exposure and measurable response
a graphic plotting of the distribution of cases by time of onset - has one mode that aims to identify the cause of a disease outbreak
a table that tabulates data according to two dimensions (2 by 2 tables) - the ones with exposed and unexposed and disease and no disease
A = Exposure is present and disease is present.
B = Exposure is present and disease is absent.
C = Exposure is absent and disease is present.
D = Exposure is absent and disease is absent.
any conjecture cast in a form that will allow it to be tested and refuted
negative declaration (null hypothesis)
a hypothesis that claims no associaion
method of difference
refers to a situation in which all of the factors in two or more domains are the same except for a single factor.
method of concomitant variation
refers to a type of association in which the frequency of an outcome increases with the frequency of exposure to a factor
refers to the process of defining measurement procedures for the variables used in a study
came up with criteria for causality
the stronger the association the more likely a relationship
the association can be replicated in different settings with different people
a given disease results from a given exposure and not from other types of exposures
the disease must occur AFTER the exposure not before
more exposure increases the severity of the disease
does the relationship make sense?
does the relationship conflict in any way with basic known science?
is the relationship likely because of a similar known relationship - example one antinausea drug causes miscarriages one in the same class probably does too
multifactorial or multicausality
a disease that has multiple causes
the process of passing from observations and axioms to generalizations
the acceptable estimation of disease occurence
if a random sample of people are gathered the occurence of a disease in the sample - sampling error might make this number different from the population parameter
confidence interval estimate
a range of values that with a certain degree of probability contain the population parameter - ex. scientists could say that they're 95% certain the occurence of MS is between 1.5 and 2.5 % of the population
the ability of a study to demonstrate an association if one exists - a small sample size with a large population of people with a disease might be more significant than a large sample size with a similar occurence
What are the three types of observational studies in analytic epidemiology?
cohort studies, case control studies, and ecologic studies
What are the three types of cohort studies?
prospective, retrospective, and historical prospective
What are the two types of intervention studies?
clinical trials and community interventions
In observational epidemiologic studies, the investigator_____________ have control over the exposure factor
In an expiremental epidemiologic study, the investigator ___________ have control over the exposure factor
quasi experimental study
one in which the investigator is able to control the exposure of individuals or units to the factor but is unable to assign participants randomly to the conditions of the study.
What type of study can be descriptive or analytic?
ecologic comparison study
involves an assessment of the association between exposure rates and disease rates during the same time period
obtaining information about exposure that happened in the past (case control studies)
information about the study outcome is obtained in the future (expiremental studies and cohort studies)
conclusions that can be drawn about a disease at the group level may not be true at the individual level
a study in which the unit of analysis is a group of people rather than individuals
Ex. people from the South vs people from the North heart disease risk
an association between two variables measured at the group level
estimates of the exposure level of a group that has already been calculated previously (ex. percent of people in the south with heart disease
variables studied that may correlate with outcome (ex. income level and heart disease)
What type of study commonly uses existing data?
What are some advantages of an ecologic study?
1. provides information about the context of health
2. can be performed when individual data is not available
3. can be conducted rapidly and with minimal resources
What are some disadvantages of an ecologic study?
1. the ecologic fallacy
2. imprecise measurement of exposure
case control study
a study in which subjects are defined on the basis of the presence or absence of an outcome of interest
matched case control study
a study in which subjects are matched on the basis of sex, race, age or other variable
odds ratio (OR)
a measure of the association between frequency of exposure and frequency of outcome used in case control studies
considered an indirect measure of risk since incidence rate was not used
How would you interpret an odds ratio of 2.4?
The odds of disease are 2.4 times higher among the exposed than among the unexposed
An odds ratio of 1.0 indicates....?
no association between exposure and outcome
An odds ratio of less than 1.0 indicates...?
that the exposure may be protective
What are the advantages of a case control study?
1. Can be used to study low prevalence conditions
2. Relatively quick and easy to complete
3. usually inexpensive
4. involve smaller number of subjects
a population group or subset thereof that is followed over a period of time
prospective cohort study
design, subjects are classified according to their exposure to a factor of interest and then are observed over time to document the occurrence of new cases (incidence) of disease or other health events
What are the disadvantages of a case control study?
1. Measurement of exposure may be inaccurate
2. representativeness of cases and controls may be unknown
3. provide indirect estimates of risk using odds ratio`
4. the temporal relationship between exposure factor and outcome cannot always be ascertained
retrospective cohort study
makes use of historical data to determine exposure level at some baseline in the past; follow-up for subsequent occurrences of disease between baseline and the present is performed.
historical prospective cohort study
combines prospective and retrospective cohort study techniques
attributable risk %
(risk difference - 1)/risk difference
incidence rate in the exposed divided by incidence rate in the unexposed - used in cohort studies
attributable risk (risk difference)
difference between the risk in the exposed and unexposed groups - used in cohort studies
What are the advantages of cohort studies?
1. permit direct observation of risk
2. exposure factor is well defined
3. can study exposures that are uncommon in the population
4. The temporal relationship between factor and outcome is known
What are the disadvantages of cohort studies?
1. expensive and time consuming
2. complicated and difficult to carry out
3. subjects may be lost to follow up during the course of the study
4. exposure can be misclassified
population risk difference
incidence rate in total population - incidence rate in unexposed population
What is the difference between a case control and a cohort study?
A cohort study uses exposure level to study disease while a case control study uses disease to look at exposure
an investigation involving intentional change in some aspect of the status of the subjects, e.g., introduction of a preventive or therapeutic intervention)
randomized control trial
"an epidemiological experiment in which subjects in a population are randomly allocated into groups, usually called study and control groups, to receive or not to receive an experimental preventive or therapeutic procedure, maneuver, or intervention
a clinical trial meant to determine whether something can prevent disease
a clinical trial meant to determine whether something can help treat disease
a research activity that involves the administration of a test regimen to humans to evaluate its efficacy and safety
How many phases do clinical trials generally have?
at least three (the first two are generally not randomized while the third is)
a clinical trial in which participants may be switched between treatment groups
an intervention designed for the purpose of educational and behavioral changes at the population level - usually quasi-experimental design
the determination of whether the program meets stated goals and is justified economically
one's ability to generalize from the results of the study to an external population
a type of research in which the investigator manipulates the study factor but does not assign individual subjects randomly to the exposed and nonexposed groups (ex. used in public health interventions)
a type of error that arises when values (statistics) obtained for a sample differ from the values (parameters) of the parent population
refers to the degree to which the study has used methodologically sound procedures (ex. random sampling)
systematic deviation of results or inferences from truth
a type of bias in which study participants behavior changes because they know they're in a study
cases often know more about their exposure than the controls
distortions that result from procedures used to select subjects and from factors that influence participation in the study. A distortion in the estimate of the effect due to the manner in which subjects are selected for the study
healthy worker affect
observation that employed populations tend to have a lower mortality experience than the general population
the distortion of a measure of the effect of an exposure on an outcome due to the association of the exposure with other factors that influence the occurrence of the outcome
a plan or course of action, as of a government, political party, or business, intended to influence and determine decisions, actions, and other matters
a policy that pertains to the health arena, for example, in provision of healthcare services, dentistry, medicine, or public health.
the steps in the policy making process
policy cycle steps
1. policy definition, formulation, and reformulation
2. agenda setting
3. policy establishment
4. policy implementation
5. policy assessment
people involved in making the policies such as legislature
individuals, organizations, and members of government who are affected by policy decisions
policy definition, formulation, and reformulation
the processes of defining the problem for which the policy actors believe that policies are necessary
refers to setting priorities, deciding at what time to deal with a public health problem or issue, and determining who will deal with the problem
the formal adoption of policies, programs, and procedures that are designed to protect society from public health hazards
the phase of the policy cycle that focuses on achieving the objectives set forth in the policy decision
the determination of whether the policy has met defined objectives and related goals
statements of policy intended to be assessed using information from a monitoring program
Ex. unclean energy sources will be reduced by 10% in the next 5 years
evidence based public health
refers to the adoption of policies, laws, and programs that are supported by empirical data
cost effectiveness analysis
a procedure that contrasts the costs and health effects of an intervention to determine whether it is economically worthwhile
the likelihood of experiencing an adverse affect
a process for identifying adverse consequences and their associated probability
In what two ways do laypeople generally determine risk?
"dread risk" and "unknown risk"
What are the four steps of risk assessment?
1. hazard identification
2. dose-response assessment
3. exposure assessment
4. risk characterization
examines the evidence that associates exposure to an agent with its toxicity and produces a qualitative judgment about the strength of that evidence, whether it is derived from human epidemiology or extrapolated from laboratory animal data
the capability of an agent or a situation to have an adverse effect. A factor or exposure that may adversely affect health
dose response assessment
the relationship between the amount of exposure and the occurrence of the unwanted health effects
the procedure that identifies populations exposed to the toxicant, describes their composition and size, and examines the roots, magnitudes, frequencies, and durations of such exposures
estimates of the number of excess unwarranted health events expected at different time intervals at each level of exposure
steps taken to control exposure to toxic chemicals in the environment
Ex. recalling bad products, testing substances before marketing them, etc.
screening for disease
the presumptive identification of recognized disease or defects by the application of tasks, examinations, or other procedures that can be applied rapidly - confirmation of disease is still required after screening
screening the whole population regardless of risk
screening only those people at risk - generally more efficiency
the ability of an instrument to give a consistent result
the ability of an instrument to give the true measurement
the ability of the test to identify correctly all screened individuals who actually have the disease
calculated by taking the true positives/ true positives plus true negatives
a perfectly sensitive test would be 100%
a definitive diagnosis that has been determined by biopsy, surgery, autopsy, or other method and has been accepted as the standard
the ability of the test to identify only nondiseased individuals who actually do not have the disease
true negatives/ false positives and true negatives
positive predictive value
the proportion of individuals screened positive by the test who actually have the disease
true positives/ true positives and false positives
negative predictive value
the proportion of individuals screened negative by the test who actually are negative
true negatives/true negatives and false negatives
the process of making policies legitimate, meaning to be acceptable to the norms of society
A group of persons working on behalf of or strongly supporting a particular cause, such as an item of legislation, an industry, or a special segment of society
infectious disease (communicable disease)
"an illness due to a specific infectious agent or its toxic products that arises through transmission of that agent or its products from an infected person, animal, or reservoir to a susceptible host, either directly or indirectly through an intermediate plant or animal host, vector, or the inanimate environment
a disease caused by a parasite
the entry and development or multiplication of an infectious agent in the body of persons or animals
What are the three components of the epidemiologic triangle? (in infectious epidemiology)
agent, host, and environment
where the disease causing agent may exist
a person or animal that becomes susceptible to the disease agent
a factor that causes the infection
the capacity of an agent to enter and multiply in a susceptible host and thus produce infection or disease
the severity of the disease produced, i.e., whether the disease has severe clinical manifestations or is fatal in a large number of cases
a toxic substance produced by a living organism
the host's ability to resist infection by the agent
an invading substance that stimulates antibody formation
immunity that is acquired from antibodies produced by another person or animal - short term immunity
the time interval between invasion by an infectious agent and the appearance of the first sign or symptom of the disease.
the resistance of a community to an agent since the majority are protected
the infection does not show obvious clinical signs or symptoms
Ex. HIV - can be transmitted but often doesn't have symptoms
the time interval between lodgment of an infectious agent in a host and the maximal communicability of the host
What is the difference between generation time and incubation period?
incubation period only refers to clinically apparent cases of disease while generation time applies to both clinically apparent and subclinical cases of disease
a person or animal that harbors a specific infectious agent without discernible clinical disease, and which serves as a potential source of infection
the first case of a disease to come to the attention of authorities
when an infectious disease agent is habitually present in an environment
a place where infectious agents normally live and multiply; the reservoir can be human beings, animals, insects, soils, or plants
an infection or infectious agent transmissible under natural conditions from vertebrate animals to humans
portal of exit
the site from which the agent leaves that person's body
Ex. respiratory passages, the alimentary canal, the genitourinary system, and skin lesions
direct and essentially immediate transfer of infectious agents to a receptive portal of entry through which human or animal infection may take place
Ex. touching, kissing, sexual intercourse
portal of entry
where the agent enters the body
Ex. skin, respiratory system, eyes, etc.
contaminated, nonmoving objects
Ex. blood on unclean needles
intermediary sources of infection such as vehicles, droplet nuclei (particles), and vectors
Ex. airborne infections, foodborne diseases
living insect or animal that is involved with the transmission of disease agents
Ex. ticks - lyme is a vector born disease
vaccine preventable diseases
conditions that can be prevented by vaccination (immunization), a procedure in which a vaccine is injected into the body.
an inanimate object that carries infectious disease agents; Ex. the classroom doorknob, used towels found in a locker room, or carelessly discarded tissues.
emerging infectious disease
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
the deliberate release of viruses, bacteria, or other germs (agents) used to cause illness or death in people, animals, or plants.
symptoms that hint at a disease
Ex. fever, nausea, vomiting
A graphic plotting of the distribution of cases by time of onset
common source epidemic
outbreak due to exposure of a group of persons to a noxious influence that is common to the individuals in the group
a type of common-source epidemic that occurs when the exposure is brief and essentially simultaneous and the resultant cases all develop within one incubation period of the disease
a type of incidence rate used when the oc¬ currence of disease among a population at risk increases greatly over a short period of time, often related to a specific exposure
ill/ill + well *100
What social and behavioral dimensions affect health?
poverty, discrimination, stress, lifestyle practices
the choice of behavioral factors that affect how we live; these choices often are a function of social influences
studies the social distribution and social determinants of states of health
Ex. effects of support networks on health outcomes, socioeconomic status, etc.
the study of the role of behavioral factors in health
Ex. lack of exercise and heart disease
a physical, chemical, or emotional factor that causes bodily or mental tension and may be a factor in disease causation
What are the two categories of stressful life events?
positive and negative stress - positive good stress like graduation or negative like the death of a family member - both take a tole on the body though
stressful life events that take place over a prolonged period of time - positive or negative
How long do PTSD symptoms last?
at least one month
help that we receive from other people when we are under stress
techniques for managing or removing sources of stress
second hand smoke - the involuntary breathing of cigarette smoke by nonsmokers
a condition that contributes to decay and loss of teeth. The cause is reduced output of saliva, increased consumption of sugary carbonated beverages, and neglect of personal hygiene
body weight in kilograms divided by height in meters squared
studies the occurrence of mental disorders in the population
the co-occurrence of two or more mental disorders, for example, major depression and substance use disorder
black box epidemiology
epidemiologic associations between exposure and health outcomes in which the cause is unknown
the identification of inherited factors that influence disease, and how variation in the genetic material interacts with environmental factors to increase (or decrease) risk of disease
Ex. whether diseases cluster in families
Human Genome Project (HGP)
aimed to identify all of the genes in human DNA -
a subfield of epidemiology that uses molecular markers in addition to genes to establish exposure-disease relationships.
genetic marker of susceptibility
a host factor that enhances some step in the progression between exposure and disease such that the downstream step is more likely to occur
denotes those diseases for which two copies of an altered gene are required to increase risk of the disease
refers to a situation in which only a single copy of an altered gene located on a nonsex chromosome is sufficient to cause an increased risk of disease.)
refers to the study of diseases and conditions (occurring in the population) that are linked to environmental factors
Ex. exposure to air pollution, toxic chemicals, drinking water, etc.
gradual increase in the earth's temperature
What three factors must be present to classify something as a major structural birth defect?
1. result from a malformation, deformation, or disruption in one or more parts of the body
2. are present at birth
3. have a serious, adverse effect on health, development, or functional ability
Ex. cleft foot
Who collects information about work related injuries?
The US department of Labor and statistics
the distribution and determinants of injuries (such as intentional and unintentional) in the population.
an unintentional incident that could not have been prevented - an act of God
monitoring levels of excreted drugs in the sewer system in order to assess the level of illicit drug use in the community
the use of epidemiological reasoning, knowledge, and methods in the investigation of public health problems that may have been caused by or associated with intentional and/or criminal acts