CHAPTER 2:2 - 3 Flashcards
the occurrence and distribution of health such as disease, death, deformities or disabilities on human population.
Epidemiology
Concerned with the study of probable factors that influence the development of these health conditions.
Used to analyze the different factors that contribute to disease development.
Epidemiology
inanimate or living organism that cause disease, they may be biologic, chemical, physical, mechanical or nutritive; its characteristics can be described in terms of virulence, toxicity, intensity, impact or deficiency/excess.
Agent
any organism that harbors and provides nourishment for another organism.
Host
Host characteristics can be described in terms of their susceptibility or resistance against effects of a particular agent and may be influenced by the demographic and biologic factors along w/ personal habits.
What is “immunologic experience” called
Specific resistance
results from intact skin and mucous membrane, good hygiene, reflexes like coughing.
Non-specific resistance
represents the immunity and susceptibility levels of individuals comprising the population.
Herd immunity
Ratio as to how many midwives are needed within a community
1:5,000
the sum total of all external conditions and influences that affects life and development of an individual organism.
Environment
Refers to the physical, biologic and sociological environments.
Ratio as to how many nurses are needed within a community
1:20,000
3 models that explain the Multiple Causation Theory or the Ecologic Concept of Disease
a. Wheel
b. Web
c. Ecological Triad
Multiple Causation Theory or the Ecologic Concept of Disease
- gives emphasis on the role of the genetic make-up of the host(inner core).
- the middle core represents the host’s characteristics like sex, age and behaviors.
- the outer core represents the biologic, physical and social environment.
Wheel Model
Multiple Causation Theory or the Ecologic Concept of Disease
developed to further the understanding of the dynamic interrelations among various personal and environmental factors.
Ecological Triad
Web Model:
Web of Causation:
- phenotype
- behaviour
- environment
- workplace
- unknown factors
- genes
- microbes
Multiple Causation Theory or the Ecologic Concept of Disease
Depicts the intricate interrelationships of the various socio-demographic characteristics and behaviors of the host as well as the numerous environmental factors.
Web Model
The Epidemiologic Triangle consists of three component:
- Host
- Agent
- Environment
Three components of the environment:
- Physical environment
- Biological environment
- Socio-economic environment
component of the environment:
composed of the inanimate surrounding such as the geophysical condition of the climate.
Physical environment
component of the environment:
makes up the living things around us such as plants and animal life.
Biological environment
component of the environment:
may be in the form of level of economic development of the community, presence of social disruptions and the like.
Socio-economic environment
The model implies that each must be analyzed and understood for comprehensions and prediction of patterns of a disease.
The Epidemiologic Triangle
A change in any of the component will alter an existing equilibrium to increase or decrease the frequency of the disease.
Stages in the Natural Life History of Disease:
- Pre-pathogenesis or susceptibility
- Pathogenesis
Stage in the Natural Life History of Disease:
disease has not developed but factors that favor its occurrence are present
Pre-pathogenesis or susceptibility
Three substages of Pathogenesis:
- Pre-symptomatic disease or early pathogenesis
- Discernible lesion
- Advance disease
Stage in the Natural Life History of Disease:
disease has developed
Pathogenesis
substage of Pathogenesis:
individual has no symptoms that indicate presence of illness but in fact, pathogenic changes has begun.
Pre-symptomatic disease or early pathogenesis
substage of Pathogenesis:
changes may be detectable through sophisticated laboratory tests; early signs and symptoms of disease are developing.
Discernible lesion
substage of Pathogenesis:
anatomical or functional changes have produced recognizable signs and symptoms.
Advance disease
Levels of Disease Prevention
- Primary Prevention
- Secondary Prevention
- Tertiary Prevention
Level of Disease Prevention:
includes efforts to control the underlying cause or condition that results in disability.
Primary Prevention
Level of Disease Prevention:
aims at preventing and existing illness or injury from progressing to long-term disability.
Secondary Prevention
Level of Disease Prevention:
refers to rehabilitation and special education service to mitigate disability and improve functional and participatory or social outcomes once disability has occurred.
Tertiary Prevention
What stage in the Natural Life History of Disease:
* Interrelations of various host agent and environment factors bring host and agent together
* Disease provoking stimulus is produced in the known host
Pre-pathogenesis
Specific Intervention: Health promotion Specific Protection
Primary prevention aims to prevent development of disease
Substage of Pathogenesis:
- Interaction of host and stimulus
- Stimulus or agent becomes established
- Beginning tissue and physiological changes
Early pathogenesis
Specific Intervention: Early diagnosis and prompt treatment
Secondary Prevention aims to:
* Promptly diagnose and treat disease
* Prevent spread of disease to healthy population
* Prevent complications and sequel
* Shorten period of disability
Substage of Pathogenesis:
- Clinical recognition of disease is possible through laboratory or other test that detect early physiological changes
- Patient develops early symptoms
Discernible Lesion
Specific Intervention: Disability limitation
Tertiary Prevention
* Arrest disease process to prevent further complications and sequelae
Substage of Pathogenesis:
- Disability
- Defect
- Chronic state
- death
Advanced Disease
Specific Intervention: Rehabilitation
- Limit disability
- Prevent Death
Cause of a Disease:
refers to the fact that the factor must be present for the disease to occur
Necessary cause
any event, condition, characteristics or a combination of these factors that play important role in producing the disease
Cause of a Disease
Cause of a Disease
indicates that if a factor is present, the disease can occur, but the factor’s presence does not always result in the disease’s occurrence.
Sufficient cause
It states that if there is a concurrence of two variables more often than would be expected by chance, then the two variables are said to be associated.
Association
Does not necessarily imply a causal relationship
probability of an unfavorable event such as disease, disability, defect or even death
Risk
Factors associated with increased risk of a disease:
- Predisposing
- Enabling
- Reinforcing
Factor associated with increased risk of a disease:
any characteristics of an individual, a community or an environment that predisposes behavior or other conditions related to health; includes knowledge, belief and attitude but may include factors such as socio-economic status.
Predisposing
Factor associated with increased risk of a disease:
any characteristic of an individual, group or the environment that facilitates or make possible a certain health behavior or other conditions affecting health; includes any skill or resource required to attain that condition.
Enabling
Types of association:
- Spurious or artifactual association
- Indirect
- Direct or causal
Factor associated with increased risk of a disease:
any reward or punishment or any feedback following or anticipated as a consequence of health behavior.
Reinforcing
Type of association:
association when none actually exists.
Spurious or artifactual association
Type of association:
presence of a known or unknown factor common to both a characteristic and a disease may wholly or partly explain a statistical association
Indirect
Type of association:
presence of a factor w/c wholly and directly explain the cause of disease, no intervening variables.
Direct or causal
Direct or causal:
suggests that when one factor is present, disease results; conversely, when the disease is present, the factor must also be present.
One to one causal
Direct or causal:
several factors acting independently or synergistically can produce a disease
Multifactorial causation
Types of Epidemiological Approach:
- Descriptive Epidemiology
- Analytical Epidemiology
- Interventional or experimental Epidemiology
- Evaluation Epidemiology
Types of Epidemiological Approach:
Concerned with describing the frequency and distribution of disease in a given population.
The nurse characterizes the disease episode by describing the characteristics of the person affected with the disease and pattern of disease onset in terms of time and place.
Descriptive Epidemiology
It is done to look for previously unidentified cases of diseases.
Case finding
It is the presumptive identification of unrecognized diseases or defects through the application of diagnostic tests or laboratory examinations and clinical assessment that can be applied rapidly and inexpensively.
Screening
Primary Goal: To detect a disease in its early stages.
It is the proportion of persons with a disease who test positive on a screening test. It measures the probability of the test correctly identifying a positive case of a disease (true-positive).
Sensitivity
It is the proportion of persons without a disease who have negative results on a screening test. It measures the probability of correctly identifying non-cases (true-negative).
Specificity
Pattern of Occurrence and Distribution:
is the intermittent occurrence of a few isolated and unrelated cases in a given locality.
Sporadic
state of resistance of a population group to a particular disease at a given time.
Herd immunity
Pattern of Occurrence and Distribution:
the continuous occurrence throughout a period of time
Endemic
- Schistosomiasis is endemic in leyte and Samar.
- Filiariasis is endemic in Sorsogon.
- Tuberculosis is endemic practically in all specific areas.
In viewing the susceptibility of the community as host, the nurse determines the characteristics of the community and its population in terms of the following:
- Herd immunity
- Exposure or contact rate
- Chance
Pattern of Occurrence and Distribution:
- Sporadic
- Endemic
- Epidemic
- Pandemic
Pattern of Occurrence and Distribution:
The cases are few and scattered, so that there is no apparent relationship between them and they occur on and off, intermittently, through a period of time.
Sporadic
Eg.: Rabies
Pattern of Occurrence and Distribution:
is a situation when there is a marked upward fluctuation in disease incidence.
Epidemic
- Bird’s Flu-there has been no cases of bird’s flu in any area of the country, so that the occurrence of few cases in a given area in a given time would constitute a bird’s flu epidemic.
Pattern of Occurrence and Distribution:
The disease is therefore always occurring in the locality and the level of occurrence is more or less constant through a period of time.
Endemic
- Schistosomiasis is endemic in leyte and Samar.
- Filiariasis is endemic in Sorsogon.
- Tuberculosis is endemic practically in all specific areas.
Pattern of Occurrence and Distribution:
is the simultaneous occurrence of epidemic of the same disease in several countries. It is another pattern of occurrence from an international perspective.
Pandemic
Eg.: Covid-19
refers to opportunities for progressive transfer of an agent to a new host
Exposure or contact rate
possibility of contact between the source of infection and susceptible individual
Chance
What are employed in investigating patterns of disease and cause in individuals.
Case-control and cohort studies/follow-up/incidence studies
- Attempts to analyze the causes or determinants of disease through hypothesis testing.
- It consists of hypothesis-testing of causal
Analytical Epidemiology
What are utilized in analyzing patterns of disease and cause in population.
Correlation or ecologic studies
Aims to test effectiveness or reasonableness of intervention programs designed to prevent and control diseases utilizing randomized controlled or clinical trials, field or community trials.
Interventional or experimental Epidemiology
- Attempts to measure the effectiveness of different health services and intervention programs.
Evaluation Epidemiology
