exam 3 Flashcards
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.
What triggers an investigation of a disease?
the severity of the disease, the potential for spread, the availability of resources, and sometimes by political considerations or the level of concern among the general public.
Steps in the outbreak investigation of disease
- What is the problem
- what is the cause of the problem
- How do we stop the spread of the problem
Know the difference between endemic and epidemic.
*endemic: (no end) the constant presence of a disease within a geographic area or a population. Pertussis is endemic in the United States.
*epidemic: refers to the occurrence of disease in a community or region in excess of normal expectancy.
Where have nursing intervention efforts been focused regarding STDs?
PREVENTION: Behavior Modification, vaccination early detection, and education
*primary:
HIV is becoming a young person’s disease. Cost/burden of disease
*Lifetime care: costly
*Huge impact on society, blame, discrimination
*Magnified by the fact that groups with HIV tend to be ostracized ex: Homosexual men or IV drug users.
*2016 21% new HIV cases are 13–24-year old’s
Name 2 sources of financial assistance for HIV treatment
Medicare, medicaid, Ryan White HIV/AIDS treatment extension Act, ADAP (AIDS Drug Assistance Program)
Know the 3 stages of HIV. What are the characteristics of each?
*Stage 1 primary infection within 1 month of contracting virus
- Mononucleosis- lasts few weeks
- DC4 WBC decreased when virus most plentiful
- Antibody tests usually negative at this time
*Stage 2 3wks-6months (varies) after infection antibodies appear in blood but not protective
*Stage 3 symptomatic disease AIDS
- after several years last stage develops immune system declines
- Opportunistic disease develops because of low CD4 T lymphocyte count <200/ml
- TB, Pneumocystis carinii
AIDs is dx based on what White blood cell count?
CD4 WBC decreased when virus most plentiful
Be aware of the 5 HIV infection states.
0,1,2,3, unknown
What is HAART?
Highly active antiretroviral therapy
* has greatly increased the survival time of persons with HIV/AIDS.
*adherence is imperative
What testing is different about newborns from HIV Pos. mothers?
*newborns of infected mothers must be tested using DNA or RNA bc their antibodies are not their own
* it is recommended that HIV testing be a routine part of prenatal care and that all pregnant women be tested for HIV
* The EIA test is not valid because it tests for antibodies, which in the infant reflect passively acquired maternal antibodies.
Modes of transmission HIV
blood, semen, transplanted organs, vaginal secretions, breast milk, needle sharing, mother to baby at birth
What area of the US has the highest HIV prevalence rate?
the southern United States and the U.S. territories of the Virgin Islands and Puerto Rico report the highest rates
Note the ethnic distribution of HIV
HIV has disproportionately affected minority groups. African Americans have the largest HIV disease burden
Is HIV reportable and how it is reported?
*Confidential reporting is required in all states
* Anonymous
Name the 2 tests used to check for HIV?
*CD4 T lymphocyte count
*EIA enzyme linked immunosorbent assay and Western blot
Home testing is available and accurate but needs what else?
Needs confirmed by physician
What is the difference between confidential testing and anonymous testing?
*Confidential testing involves reporting by identifying the person’s name and other identifying information; this information is considered protected by confidentiality.
*anonymous testing, the client is given an identification code number that is attached to all records of the test results and is not linked to the person’s name and address
CDC Voluntary yearly screening is recommended for what age group?
15-65 years old
What are the advantage/disadvantage of anonymous testing?
*Advantage: The anonymity eliminates their concern about the possibility of arrest or discrimination.
*Disadvantage: anonymous testing does not allow for follow-up if the test is positive because the client’s name and address are not available.
What accounts for nearly all the HIV in children?
Perinatal transmission accounts for nearly all HIV infection in children and can occur during pregnancy, labor and delivery, or breastfeeding.
What happens that impoverishes many families dealing with HIV?
Cost of treatment for chronic disease