Epidemiology Flashcards
What is epidemiology?
Study of the distribution of factors that determine health-related states or events in a population, and the use of this information to control health problems (Stanhope & Lancaster, 2017).
What are the components of epidemiology?
Illness and disease are not randomly distributed in the population.
People have characteristics that predispose them or protect them.
Determinants of Health
Health surveillance/monitoring
What is the overall goal of epidemiology?
Maintaining health and preventing illness and injury and other.
What is the difference between epidemiology and clinical medicine?
Epidemiology studies populations and the determinants of health that influence the health state/disease. Seeks to understand the context of peoples' lives.
What are the key concepts of epidemiology? (3)
Causality
Risk
Rates of occurrence
What is the purpose of epidemiology?
To identify origin and causal links between contributing factors and resulting states of health and illness.
What are the uses of epidemiology? (6)
Understanding of the factors contributing to health and disease.
Develop health promotion and disease prevention measures.
Detect and characterize emerging infectious agents.
Evaluate health services and policies.
Community health nursing practice.
To diagnose the health status of a population
What is causality?
Causality: one event is the result of another event.
What is risk?
The likelihood/probability that the event will likely occur. Looked at within a particular time frame.
What is “rates of occurrence”?
Statistical measures that indicate the extent of a health problem in the population.
Who was John Snow?
The first epidemiology, look at the cholera epidemic in the 1850s in London, mapped where the outbreak was most prevalent, why was that, what was the sources of the cholera, and conducted that the water was the source.
What role did Florence Nightingale play in epidemiology?
Looked at the environmental conditions, morbidity/death rates, disease rates
What are four models used in epidemiologic investigation?
Epidemiologic Triangle
Web of Causation
Iceberg Model
Life Course Approach
What is the Epidemiologic triangle? (model used in epidemiologic investigation)
Seeks to explain the relationship between the host, the agent and the environment
What is the Web of Causation? (model used in epideiologic investigation)
Explores the interplay of multiple factors and identifies direct and indirect causes of disease.
What is the Iceberg Model? (model used in epidemiologic investigation)
Completes the clinical picture to gain understanding of the complete picture
What is the Life Course Approach?
Early life factors influence health in adulthood.
What are the three components of the epidemiological triangle?
Host
Agent
Environment
What is a host (part of the epidemiologic triangle)?
The person or animal (living species). Can be a group.
What is an agent (part of the epidemiologic triangle)?
Animate or inanimate factor which must be present for the disease/condition to develop.
What are some examples of different types of agents?
Chemical agent (mercury, asbestos, lead, tobacco) Infectious agent (virus, bacteria, fungi, parasites) Physical agent (heat, cold, radiation, trauma)
What is the environment (part of the epidemiologic triangle)?
External to the host, influences host and agent.
What are some factors/examples of environment (as part of the epidemiologic triangle)?
Physical (climate, rainfall, pollution)
Biological (water resservoir/habitats)
Social (working conditions, socioeconomic conditions (housing), access to healthcare)
What are the three parts of the course of the disease/condition from onset to resolution?
Preceding events
Events throughout
Outcomes
What are the stages of a disease/condition?
Pre-exposure (primary prevention)
Pre-clinical (secondary prevention)
Clinical
Resolution
What is the concept of causality or causation?
The notion that one event is the result of another event.
What are the four eras of perspectives on what causes diseases?
Religious era (2000 BC to 600 BC) Environmental era (~400 BC) Bacteriologic era (mid 1800's) - beginning of epidemiological study (scurvy, cholera) Era of multiple causation (current perspective) with focus on social determinants of health
What are the seven criteria for causality?
- Strength of association
- Coherence/plausability
- Temporality
- Consideration of alternate explanations
- Dose-response relationship
- Consistency of the association
- Specificity of association
What is strength of association? (one of the criteria for causality)
Correlations; usually measured statistically (relative risk ratios)
What is coherence/plausability? (one of the criteria for causality)
Logical and biologically plausible
What is temporality? (one of the criteria for causality)
Exposure must precede disease/condition
What is consideration of altenate explanations? (one of the criteria for causality)
Consider confounding variables
What is dose-response relationship? (one of the criteria for causality)
Persons most exposed are the most ill
What is consistency of the association? (one of the criteria for causality)
Can the findings be replicated? Cessation of exposure
What is specificity of association? (one of the criteria for causality)
Cause linked to a specific disease/condition
Which criterion is absolutely essential when establishing a cause and effect relationsip?
Temporality
Which criterion is the weakest when establishing a cause and effect relationship? Why?
Specificity - because many diseases have more than one cause
What is risk?
The probability/likelihood that a particular condition will occur.
What is risk influenced by?
Influenced by the broad determinants of health
How do we determine who is the target group for an intervention?
Aggregates within the population identified to be at risk become the target group for interventions designed to prevent or control the health concern.
What are rates of occurrence?
Statistical measures that indicate the extent of health problems in a group, community of population.
What are two rates of occurrence that are of interest to public health nursing?
Mortality
Morbidity
What are some types of mortality rates?
Infant mortality
Crude mortality
Specific mortality
What are some types of morbidity rates?
Incidence
Prevalence
What is epidemiologic investigation?
A systematic process to study states of health and illness in an effort to control disease and promote health.
What are the parallels between the nursing process and epidemiologic investigation?
Defines the condition or health outcome.
Determines the natural history of the condition.
Identifies strategic points of control.
Designs, implements, and evaluates control strategies.
What are some sources of data for epidemiologic investivation?
Routinely collected data.
Data collected for a specific purpose
Original data
What are some examples of routinely collected data? (a source of data for epidemiologic investigation)
Vital statistics
Federal census
CCHS
PH surveillance
What are some examples of data collected for a specific purpose? (a source of data for epidemiologic investigation)
Insurance records, surveillance systems
What are some examples of original data? (a source of data for epidemiologic investigation)
Stats Canada
CIHI
Health surveys
What are some types of epidemiological investigation? (4)
Descriptive (what, who, where, when)
Analytical (how and why)
Ecological Studies
Experimental/intervention studies
What are descriptive epidemiological investigations? (what are the characteristics of this type of epidemioloigical investigation)?
Distribution of a given state of health.
Distinguishes characteristics of those with disease and those without.
Strictly observational.
Generates hypotheses.
What are analytical epidemiological investigations? (What are the characteristics of this type of epidemiological investigation)?
Identifies causal factors and origin (etiology) AND determinants of health.
Observational (investigator does not intervene).
Test hypotheses.
What are three areas of descriptive studies?
Characteristics of person
Characteristics of place
Characteristics of time
What are “characteristics of person”? (part of descriptive studies)
Age, gender, ethnicity, education, occupation, income/socio-economic status, marital status
What are characteristics of place? (part of descriptive studies)
Geographic patterns, population density, lifestyle patterns, religion, culture, ethnicity and environmental factors
What are characteristics of time? (part of descriptive studies)
Patterns of frequency over time
What are three types of characteristics of time? (part of descriptive studes)
Secular
Cyclical
Event-related
What are ecological studies? (a type of epidemiological study)
Only aggregate data is used.
Bridges descriptive and analytical epidemiology.
What are experimental/intervention studies? (examples, two types)
Clinical trials
Community trials
What is the definition of “descriptive measures of health”?
The frequency of certain health events in a defined population during a specified period of time; typically expressed as rates
What is “crude mortality”?
Crude - all causes
everybody in a given population i.e. population of Chilliwack mortality rate
What is specific mortality?
Specific - populations or subgroups
An aggregate/subpopulation, helps identify which groups are more at risk. Typically by age, also by sex, or ethnicity.
What is cause-specific mortality?
Deaths attributed to a specific condition
What is incidence (a morbidity rate)?
Number of new cases in a year
What is prevalence (a morbidity rate)?
total cases (total living cases at present)
What are analytic measures of health? (what do they do?)
Answers the question “does a relationship exist between a health condition and a specific factor?”
What are the two ways analytic measures of health may be expressed?
Relative risk ratio
Attributable risk
What is relative risk ratio? (a type of analytic measure of health)
Determines if a relationship exists between a health condition and a suspected factor
What is attributable risk (a type of analytic measure of health)?
How much risk of developing a condition can be attributed to each known risk factor?
What is the relevance of epidemiology to public health practice?
Public health nurses have roles to play in the identification, management, treatment and prevention of health problems.
Being able to read and interpret data about trends is a basic competency for PH nursing practice.
Public health nurses are responsible for implementing health promotion and prevention that is based on an understanding of risk factors, distribution patterns, and determinants of health and illness.
How to CHNs use epidemiology?
Utilize epidemiological data.
Identify health threats.
Involved in surveillance and monitoring of disease trends.
Collect, report, analyze, interpret and communicate epidemiological data.
Communicable disease control.
Work as member of interdisciplinary team.
Nursing documentation on client records is an important source of data for epidemiological reviews.
