Module 2 Flashcards
The study of the distribution and determinants of disease and other conditions in human populations.
Section A: Epidemiology
Epidemiology
The number of new cases of a given disease in a given time period.
Section A: Epidemiology
Incidence
The number of existent cases of a given disease at a given time.
Section A: Epidemiology
Prevalence
An excess over the expected incidence of disease within a given geographical area during a specified time period.
Epidemic
An epidemic spread over a wide geographical area, across countries or continents.
Section A: Epidemiology
Pandemic
Synonymous with epidemic but often preferred when dealing with the public; in local settings, a group of people with the same disease who are epidemiologically linked.
Section A: Epidemiology
Outbreak
A group of persons with a given disease occurring in the same space and time but not epidemiologically linked. If an epidemiological link is made, may become an outbreak.
Section A: Epidemiology
Cluster
In biology, a biting insect, tick, or other organism responsible for transmitting a disease, pathogen, or parasite between persons, animals, or plants.
Section A: Epidemiology
Vector
A place in which an infectious agent can survive but may or may not multiply, for example, Pseudomonas in nebulizers and hepatitis B on the surface of a
hemodialysis machine.
Section A: Epidemiology
Reservoir
A disease transmitted from animals to humans (e.g., cat scratch fever, psittacosis).
Section A: Epidemiology
Zoonosis
An inanimate object on which organisms may exist for some period of time, for example, a contaminated piece of medical equipment.
Section A: Epidemiology
Fomite
The resistance of a group to invasion and spread of an infectious agent, based on the immunity of a high proportion of individual members of the group.
Section A: Epidemiology
Herd immunity
The probability or likelihood of an event occurring.
Section A: Epidemiology
Risk factor
An infection that runs a course similar to that of clinical disease but below the threshold of discernible clinical symptoms.
Section A: Epidemiology
Infection—unapparent, asymptomatic, or subclinical
An infection that results in clinical signs and symptoms of a recognizable disease process.
Section A: Epidemiology
Infection—apparent, clinical, or symptomatic
An infection that is not present at the time of admission to a healthcare facility but is temporally associated with admission to or a procedure performed in the facility; may also be related to a recent hospitalization.
Section A: Epidemiology
Healthcare-associated infection (HAI)
An infection that is present on admission to a healthcare facility and has no association with a recent hospitalization.
Section A: Epidemiology
Community-acquired infection
A component of the epidemiological triangle; refers to a human or other animal.
Section A: Epidemiology
Host
A component of the epidemiological triangle; consists of all external factors associated with the host.
Section A: Epidemiology
Environment
A component of the epidemiological triangle; may be a bacteria, virus, fungus, protozoan, helminth, or prion.
Section A: Epidemiology
Agent
A biological, physical, or chemical entity capable of causing disease.
Section A: Epidemiology
Causative agent
A person who shows no recognizable signs or symptoms of a disease but is capable of spreading the disease to others.
Section A: Epidemiology
Carrier
Those who have recovered from a disease but still have organisms present that can be transmitted.
Section A: Epidemiology
Convalescent carriers
Persons who may continue to have organisms present for very long periods of time.
Section A: Epidemiology
Chronic carriers
Persons who may continue to have organisms present for very long periods of time.
Section A: Epidemiology
Sustained carriers
Persons who periodically shed organisms.
Section A: Epidemiology
Intermittent carriers
In the chain of infection, the path by which an infectious agent leaves the reservoir.
Section A: Epidemiology
Portal of exit
The method by which an organism reaches a susceptible host.
Section A: Epidemiology
Mode of transmission
A mode of transmission that features person-to-person spread with actual physical contact occurring between a source and a susceptible host.
Section A: Epidemiology
Direct contact
A mode of transmission that occurs when a patient comes in contact with a contaminated intermediate object or fomite.
Section A: Epidemiology
Indirect contact
A mode of transmission that occurs when the infectious agent spends only a brief period passing through the air and can be inhaled at that time.
Section A: Epidemiology
Droplet transmission
An efficient mode of transmission that may involve varying distances between the source and the host.
Section A: Epidemiology
Airborne spread
The mechanical transfer of microorganisms by a vector, such as a fly on food.
Section A: Epidemiology
External vector-borne transmission
Involves the transfer of infectious material directly from the vector into the new host, such as occurs with mosquitoes and malaria.
Section A: Epidemiology
Internal vector-borne transmission
In the chain of infection, the means by which an infectious agent enters a susceptible host.
Section A: Epidemiology
Portal of entry
A system for routine, ongoing, and systematic collection, analysis, interpretation, and dissemination of surveillance data to identify infections (i.e., HAI and community-acquired), infection risks, communicable disease outbreaks, and to maintain or improve resident health status.
Section B: Surveillance Design
Surveillance
Surveillance that involves trained individuals (such as IPs) actively looking for healthcare-associated infections using standardized definitions and protocols.
Section B: Surveillance Design
Active surveillance
Surveillance that relies on others (e.g., physicians, nurses, or the microbiology laboratory) who are not trained on surveillance methods or primarily responsible for surveillance activities to report healthcare-associated infections.
Section B: Surveillance Design
Passive surveillance
The set of protocols and guidelines that will direct surveillance activities
Section B: Surveillance Design
Surveillance plan
A measure that indicates the result of the performance (or nonperformance) of functions or processes.
Section B: Surveillance Design
Outcome measure
A measure that focuses on a process or the steps in a process that lead to a specific outcome.
Section B: Surveillance Design
Process measure
Detail the steps necessary for reaching the goals and addressing the issues identified during surveillance.
Section B: Surveillance Design
Action plans
Measures and tracks all infections at a facility, across its entire population of residents and staff; also known as “comprehensive” or “whole house” surveillance.
Section B: Surveillance Design
Total surveillance
Focuses on a narrow selection of infections and pathogens; also known as “priority-directed” surveillance.
Section B: Surveillance Design
Targeted surveillance
The collection and analysis of pre-diagnostic and nonclinical disease indicators using preexisting electronic data.
Section B: Surveillance Design
Syndromic surveillance
Collecting and referencing of data in real time, with a focus on new information as it comes in.
Section C: Data Collection and Management
Concurrent data collection
Collating of data that has already been collected, with a
focus on examining what has already happened.
Section C: Data Collection and Management
Retrospective data collection
Specific conditions that qualify as infections for the purpose of surveillance data collection; they are also used in the calculation and reporting of infection rates.
Section C: Data Collection and Management
Surveillance criteria
Data that is socio-economic in nature (e.g., age, sex, race).
Section C: Data Collection and Management
Demographic data
Data related to high-volume, high-risk events within a faciility (e.g., HAIs, immunization rates).
Section C: Data Collection and Management
Event data
Data related to facility protocols and practices (e.g., standard precautions, environmental cleaning).
Section C: Data Collection and Management
Process data
Data bound by a unit of time (e.g., month, year).
Section C: Data Collection and Management
Time data
The extent to which a measure accurately reflects the concept or construct that it is intended to measure. (The Joint Commission)
Section C: Data Collection and Management
Validity
The relationship between a risk factor and an outcome, such as a disease.
Section D: Statistics
Association
The probability of developing a disease if the risk factor is present divided by the probability of developing the disease if the risk factor is not present.
Section D: Statistics
Relative risk (RR)
The probability of having a particular risk factor if a condition or disease is present divided by the probability of having the risk factor if the disease or condition is not present.
Section D: Statistics
Odds ratio (OR)
Data representing counts or values on a numeric scale.
Section D: Statistics
Quantitative data
Data representing whole numbers.
Section D: Statistics
Discrete data
Data that can be measured on a continuum or scale.
Section D: Statistics
Continuous data
Data representing qualities or characteristics.
Section D: Statistics
Qualitative data
Data split into mutually exclusive groups.
Section D: Statistics
Categorical data
The crudest level of measurement in descriptive statistics. Creates categorical data in which no order is implied by the classifications. Values cannot be measured mathematically (e.g., cannot be averaged) but frequency or percentage can be applied.
Section D: Statistics
Nominal scale
A measurement in descriptive statistics that applies ranking to categorical data on a relative scale so that each category is distinct and stands in some definite relationship to each of the other categories but does not indicate how much greater each level is than another.
Section D: Statistics
Ordinal scale
A measurement in descriptive statistics in which the exact distance between any two ordinal scale observations is known and assumed to be equal but attributes measured have no real, rational zero point.
Section D: Statistics
Interval scale
The highest level of measurement in descriptive statistics; creates interval scale observations that have an absolute, real zero point, which allows for higher levels of statistical analysis.
Section D: Statistics
Ratio scale
The process by which the population in a dataset is separated into distinct categories.
Section D: Statistics
Stratification
Used when one needs to compare the event rates of different groups, for example, if an IP wants to compare catheter-associated urinary tract infection rates for two facilities.
Section D: Statistics
Standardization
The comparison of any two quantitative values.
Section D: Statistics
Ratio
A specific kind of ratio that compares a part to the whole.
Section D: Statistics
Proportion
A specific kind of ratio that includes a unit of time, and provides information about how fast events are occurring.
Section D: Statistics
Rate
Calculation of the direction and magnitude of a relationship between two variables.
Section D: Statistics
Correlation
A way to explain the relationship between a dependent variable (y) and one or more explanatory (or independent) variables (x).
Section D: Statistics
Regression
A systematic error in study design, subject recruitment, data collection, or analysis that results in a mistaken estimate of the true population parameter. (NIH)
Section D: Statistics
Bias
A variable that is an independent cause or predictor of the exposure and the outcome and is not on the path between the exposure and the outcome; also called a confounding variable.
Section D: Statistics
Confounder
Prevalence at a specific point in time (e.g., on a given day).
Section D: Statistics
Point prevalence
Prevalence during a span of time (e.g., over the course of a given month).
Section D: Statistics
Period prevalence
A measure of the number of new cases or events within the population at risk during the identified time period.
Section D: Statistics
Incidence proportion
Represents the proportion of new cases over a particular period of time.
Section D: Statistics
Incidence rate
The proportion of persons at risk who become infected over an entire period of exposure or a measure of the risk or probability of becoming a case.
Section D: Statistics
Attack rate
A measure of the frequency of death in a defined population during a specified time (usually a year).
Section D: Statistics
Mortality rate
The set of all observations of interest to the investigator (the universe).
Section D: Statistics
Population
A group of observations selected from a population and chosen to represent the population as a whole.
Section D: Statistics
Sample
Describe how observations cluster around a middle value and locate only the center of a distribution measure; include mean, median, and mode.
Section D: Statistics
Measures of central tendency
The sum of all values divided by the total number of values.
Section D: Statistics
Mean
The midpoint of a set of observations
Section D: Statistics
Median
The observation that occurs most frequently in a data set.
Section D: Statistics
Mode
The difference between the smallest and largest values in a data set.
Section D: Statistics
Range
A bell-shaped curve on a graph in which the
distribution (spread) of the values is even on both sides of the mean (both halves are equal) and the mean, median, and mode are all equal.
Section D: Statistics
Normal distribution
The distribution of samples taken.
Section D: Statistics
Sampling distribution
The distribution of data around the mean.
Section D: Statistics
Dispersion
The difference between an individual value in a data set and the mean value.
Section D: Statistics
Deviation
The deviation around the mean of a distribution.
Section D: Statistics
Variance
A measure that reflects the distribution of values around the mean; it is the average of all deviations in a data set and indicates how spread out the data are around the mean.
Section D: Statistics
Standard deviation
The cutoff point for accepting or rejecting the null hypothesis. In a one-tailed test, this occupies just one end of the distribution (bell curve), but, in a two-tailed test, it takes up both ends of the distribution.
Section D: Statistics
Rejection region
The probability value arbitrarily chosen by the
researcher as the desired level of probability at which one may feel secure in rejecting the null hypothesis; typically set at 0.05 or 0.01.
Section D: Statistics
Level of significance
The probability of observing a sample in which the test statistic is greater than or equal to the test statistic for the sample that was actually observed.
Section D: Statistics
p value
The ability of the indicator to accurately and
consistently identify the events it was designed to identify across multiple healthcare settings. (The Joint Commission)
Section D: Statistics
Reliability
Occurs when the null hypothesis is rejected when it is actually true or when significance is attributed when there actually is none.
Section D: Statistics
Type I error
Occurs when the null hypothesis is accepted when it is actually false or when significance is not attributed when it actually exists.
Section D: Statistics
Type II error
A measure of the probability that a test correctly identifies as positive persons who have a disease.
Section D: Statistics
Sensitivity
A measure of the proportion of persons with a positive test who have a disease.
Section D: Statistics
Positive predictive value (PPV)
A measure of the probability that a test correctly identifies persons without a disease as negative.
Section D: Statistics
Specificity
A measure of the proportion of persons without a disease who test negative.
Section D: Statistics
Negative predictive value (NPV)
A table with two outcome columns (e.g., disease and no disease) and two exposure rows (e.g., exposed and not exposed).
Section D: Statistics
2 by 2 table
The ability of a test to detect a specified difference.
Section D: Statistics
Power
A data set presented in rows and columns.
Section E: Presenting Surveillance Activity
Results
Table
A form of visual data presentation used when the magnitudes of different events is important or when one wants to compare parts of the bigger picture.
Section E: Presenting Surveillance Activity
Results
Chart
Shows the proportion that a group represents within the whole population.
Section E: Presenting Surveillance Activity
Results
Pie chart
Presents data as side-by-side bars for an easy
comparison of magnitudes, frequency distributions, and time-series data.
Section E: Presenting Surveillance Activity
Results
Bar graph
A graphic of frequency distribution that looks much like a bar graph but in which each bar represents a different time interval.
Section E: Presenting Surveillance Activity
Results
Histogram
Chart used to display the same data over time, for example, the rate of ICU CLABSIs over a year; each time point is equidistant from the previous and next time points, with time running along the x axis.
Section E: Presenting Surveillance Activity
Results
Line chart
A tool for illustrating the geographic distribution of cases; uses dots or other symbols to show where each case-patient lives or was exposed.
Section E: Presenting Surveillance Activity
Results
Spot map
Map that uses different shades of chosen colors to indicate different rates of infection (or other disease/health condition), with the darker shades indicating higher rates or an increasing disease burden.
Section E: Presenting Surveillance Activity
Results
Area map
A set of methods for improving systems, processes, and outcomes; the primary goal is to recognize and understand common and special cause variations that affect a process.
Section E: Presenting Surveillance Activity
Results
Statistical process control (SPC)
The deliberate release of viruses, bacteria, or other germs (agents) used to cause illness or death in people, animals, or plants. (CDC)
Section F: Emergency Preparedness
Bioterrorism attack
A standardized management tool for meeting the demands of small or large emergency or
nonemergency situations. (FEMA)
Section F: Emergency Preparedness
Incident Command System (ICS)
A set of uniformly applied criteria for determining whether a person should be identified as having a particular disease, injury, or other health condition; it usually specifies clinical, laboratory, and other
diagnostic criteria.
Section G: Outbreak Investigations
Case definition
A document that contains information related to patient symptoms (in case there is the possibility that it is a pseudo-outbreak), medications, procedures, consults, patient locations, contact with HCP, and host of other
factors that might predispose the patients to the infection under investigation.
Section G: Outbreak Investigations
Line list
A graph in which the cases of a disease that occur during an epidemic (outbreak) are plotted according to the time of onset of illness.
Section G: Outbreak Investigations
Epidemic curve
Protocols designed to interrupt the transmission of and reduce or eliminate the occurrence of communicable diseases and infections.
Section G: Outbreak Investigations
Control measures
