exam 3 Flashcards
(117 cards)
Characteristics of each three factors in the epidemiological triangle
a way of identifying causative factors, transmission, and risk related to infectious diseases.
Host: Age, sex, Race, genetic profile, previous diseases, immune status, religion customs, occupation, marital status, family background
(Causative factor leading to health problem)
Agent: biologic (bact, viral), Chemical (poison alcohol smoke), physical (trauma radiation fire), and Nutritional (lack excess)
(Ext factors that surround the host and influence vulnerability and resistance)
Environment: temperature, humidity, altitude, crowding, housing, neighborhood, water, milk, food, radiation, pollution, noise.
How the epi triangle has evolved
The Web of Causality-interacting factors: reflects the more complex interrelationships among the numerous factors interacting, sometimes in subtle ways, to increase (or decrease) risk of disease.
4 W’s of descriptive epidemiology
*Looks at the distribution of health outcomes.
What: Health Issue of Concern what happened?
Who: Person who is it happening too?
Where: Place where was it happening?
When: Time when was it happening?
2 factors of analytical epi
*looks at the determinants of outcomes
Why/How: Causes Risk Factors Modes of transmission.
How does nursing apply epidemiological methods?
*understand factors that contribute to health and disease
*develop health promotion and disease prevention
*identify the presence of infectious agaents in individuals and groups
*design, implement and evaluate community health programs and PH policies
Hx of epidemiology
*Hippocrates (Greek) 4th century BC
*Idea of diverse causes of health/disease in a community (ecological model)
*Not until 19th century Basic epidemiology created by John Snow father of epidemiology.
20th century when it became a distinct discipline.
proportions
Type of ratio, denominator includes the numerator (expressed as a %)
rates
*ratio, measured by frequency of a health event in a defined population, usually within a specific period of time.
Numerator= # of events
Denominators= population over a period of time
risk
*probability that an event will occur during a specified period of time. (Even if it’s a small possibility… ex men and breast cancer)
*High Risk: based on genetics, behaviors, and other factors. Incidence
*No Risk: ex. Men with ovarian cancer & women with testicular cancer
Difference between incidence and prevalence
*Prevalence: amount of disease in a population. Usually expressed in %. Denominator includes the numerator . (Ex: death d/t heart disease over the number of deaths total)
*Incidence: number of new cases/ the number of people at risk. Usually expressed as so many cases per 100,000 annually.
Mortality rate is good for what?
They reflect changes in social behavior or health practices. For example, the increased lung cancer mortality rates among men and women in recent years reflect a delayed effect of increased smoking in prior years
Importance of IMR
indicator of overall population health around the world and availability of healthcare. # of infant deaths within a year versus the total number of live births
Purpose of screening and characteristics of successful screening program.
*aim is early detection and treatment, NOT a diagnostic test.
*Ask: Ethical? Justified?
reliability and validity
*validity: accuracy- measuring what is intended.
a. Sensitivity: test identifies those with condition
b. Specificity: test identifies those without condition
*Reliability: repeatability/consistency of the measure
a. Sources of error
b. Variation in what’s being measured.
c. Observer variation
d. Instrument inconsistency
sensitivity vs specificity
a. Sensitivity: test identifies those with condition
b. Specificity: test identifies those without condition
What is surveillance and how is it useful to Epidemiology?
systematic collection, analysis, and interpretation of data r/t occurrence of disease and health status of the population
What is Sentinel Surveillance?
systems and providers. representative population selected and sampled. used when it is not feasible to survey larger groups or larger geographical areas or the disease is rare.
Active and passive surveillance difference?
a. Passive: more common, less expensive (health care providers report to PH dept. standardized reports)
b. Active: uses personal contact, limited to special specific purposes. Personal/phone contact or review of lab reports
Sources of Data major types
*Secondary sources: routinely collected data (census vital records CDS data)
*Primary sources: original data collected for specific epidemiology studies
a. National center health stats
b. National hospital d/c summary and many others
Value of Comparison Groups
Key feature. Control group who does not have disease compared with those with disease
When – trends in time useful for Epidemiology: Time patterns of death/disease secular trends, Point epidemic, Sharp peaks, Cyclical patterns, Event related clusters
*Time patterns of death/disease secular trends: changes in social behavior
*Point epidemic: most clearly seen when frequently in cases is plotted against time
*Sharp peaks: concentration of cases in short time intervals
*Cyclical patterns: seasonal fluctuations (time change)
*Event related clusters = natural disaster exp by many people at the same time.
Different types of Epidemiological studies
*Cohort studies: group of people sharing some characteristics of interest. They are watched for development of a disease
a. Prospective cohort: follow over time
b. Retrospective cohort: use already available data from the past
Causality criteria
*Strength of association
*consistency of findings
*biological plausibility
*demonstration of correct temporal sequence
*Dose-response relationship
*specificity of the association
*experimental evidence
How do nurses use Epidemiology?
understand factors that contribute health and disease, develop health promotion and disease prevention interventions, identify the presence of inf agents in individuals and groups, design implement and evaluate community health programs and PH Policies.