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Flashcards in Comm Test 3: epidemiology Deck (63)
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0
Q
  • detective work, learn how to investigate
    The study of distribution(where it goes, who what where and when) to and determinants(what, who, where , when, why, and how) of health and disease. Looking at causes
  • find pt zero= signs and symptoms first, walked on plane with it/ go out to who is exposed making a web of causation, map out
    -Integrates principles of scientific research.
    -Accurate assessment and correct diagnosis.
    -Aimed at finding cause of health or disease.
    Describes disease patterns according to person, place, and time- determine where pt 0 have been and who has been in contact with
A

Epidemiology

1
Q

cause and treatment, determinants

A

Analytical epidemiology

2
Q
  • going out after all of the determinants and focused on treatment/ taking analytical epi and applying it to a situation
A

Applied epidemiology

3
Q

types of epidemiology

A

descriptive
analytical
applied

4
Q

questions that we ask

Distribution

A
Distribution--who, what, where, and when 
Person – Who is affected?
Event – What happened?
Place – Where did this happen?
Time – When did this happen?
5
Q

Determinants
may have to take a long history
could have gotten it in a hospital

A

How did the event occur?

Why did the event occur?

6
Q
  • always have to have host=pt 0, agent=tb, and environment= where it spread, precipitate this
    next distribution then determinant
A

Epidemiological Triangle

7
Q
  • good positive factor, what do you have going for you
A
  1. Agent – Etiological Factors

* epidemiological triangle

8
Q
  • med=chem bc suppression of immune system, bacteria, childhood diseases =shingles: still have virus in it, not as immune as we thought we were
    Lifestyle factors= smoking: limit immune system
    Equipment and machines in health care facility not cleaned well
    Vegs and fruit that are not washed well have organisms
A

. Agents of Disease

epidemiological triangle

9
Q
– Intrinsic Factors: hard to modify 
Genetics
Age
Gender Ex: women more susceptible to UTI
Ethnicity 
General physical condition- to a point
Behaviors- drinking, smoking, enough sleep
A

Host

10
Q

= Extrinsic Factors- things you can’t control
Ex: Work conditions, Weather, Food sources, Population density, War= agent orange bomb, economic development= third world country that doesn’t have agriculture or fresh clean water: more susceptible to a disease

A

Environment

11
Q
  • plot all factors that affect patient 0

ask about agent, enviro, host

A

Web of Causation

12
Q

: illness type of issues

A

Morbidity

13
Q

Sometimes underreported due to lack of surveillance.
– the occurrence of new cases of a disease or condition over a period of time relative to the size of the population at risk for that disease or condition during the same period of time.
-plot number of cases in each month to determine most prevalent
-want to know if it is spreading or getting worse
Most sensitive indicator of changes in health
-Can be used with chronic disease Ex: heart failure, 5 or 10 year , still valid , can use just enlarge period of time
-Usually used for short term, acute disease
* risk rate
* new cases during a given time not old / average population at geographic are
Ex: 2003 335,105 causes of gonohrea where reported in us. 2003 us pop was 290788976

A

Incidence Rate

Morbidity

14
Q

don’t confuse with incident( pop period)
The number of new cases of a disease in those who have been exposed to the disease. Ex: grade school, established first statistic then new cases of people exposed on the plane after intial
-Used when the population is exposed to an infectious disease at a given time and place.
*probability risk rate
* highly specific person limited by specific place and time period is brief
Ex: 75 people attended church picnic 46 dev gi illness

A

Attack Rates-

Morbidity

15
Q

Measures existing disease in a population at a given point in time relative to the population at the same point in time= how much it goes up
Influenced by the number of people who experience the disease and duration of the disease.
Increases when the incidence rate or duration increases.
*risk and duration
* portion of people in population who have a particular disease new and old cases/ population in the area

A

Prevalence Rate

Morbidity

16
Q
Refers to routine collection of birth and death rates. New or end of life issues 
Not to be confused with morbidity rates.
Crude death rate
Age-specific rate
Proportionate mortality rate
A

Mortality Rates

17
Q

Estimate of the risk of death for a person in a given population for that year. Ex: newborns with down syndrome what is the rate of survival
Number of deaths from any cause during a certain time interval (6months)
Use mid-year interval (June 30th)
Affected by variables of age, race, SES

A

Crude Mortality (death) Rate

18
Q
  • living in town with aging pop risk goes up because see more deaths there
  • AA higher risk of males in coronary artery disease
  • not have access to resource that they have, lifestyle issues
A

Crude Mortality (death) Rate
age
race
ses

19
Q

Number of deaths among a given age group per mid-year population as compared to the estimated population.
Characterizes a particular age group in the population.
Subgroups. 65-75 group males with heart disease

A

Age-Specific mortality Rates

20
Q

all deaths resulting from a specific cause relative to deaths from all causes.
Total number of death from any cause/ then death of specific cause
Ex: 100 deaths you had 20 deaths from CHF calculated in 100 the ratio is 1-5
-Identifies areas for intervention aimed at reducing deaths. HP 2020, LHI
-Must be taken into context.

A

Proportionate Mortality Ratio

21
Q

concept of risk

A

risk factor
attributable risk
relative risk ratio

22
Q
  • Probability of an adverse event
A

Risk

23
Q
  • Exposure to an adverse event
A

Risk factor

24
Q
  • Estimate of disease burden in a population, likely to be infected
A

Attributable risk

25
Q

Excess risk caused by the risk factor

A

Relative risk ratio-

26
Q
  • pre-pathogenesis

* immunizations

A

Primary prevention

27
Q
  • screenings

* aimed at early intervention

A

Secondary prevention

28
Q
  • rehab and restore
A

Tertiary prevention

29
Q

Purpose = identify risk factors at the earliest stage

-don’t have to be done every year

A

Screening

30
Q
  • it will produce results each time, suspect someone of having we will know and will determine results
A

Reliability screening

31
Q
  • are the results accurate
A

Validity screening

32
Q
  • correctly identifies those persons with the disease, has to be right level, won’t use till other dx test have been done, overly can have false-positives
A

Sensitivity

screening

33
Q
  • correctly identify person that does not have the disease , may get false- negatives when really sensitivity is to low= they really do have the disease
A

Specificity

screening

34
Q
  • breaking down the proportion of person of a positive test that actually have that
A

Positive predictive value

screening

35
Q
  • proportion of person of a negative test that don’t have it
A

Negative predictive value

36
Q

-not focused on intervention, tells story about what happened, focus on distribution of it how far it got and who go it
distribution of health outcomes using person, place, & time.
-Narrative regarding what happened from beginning to end
-Time affected by secular trends
-Time affected by point epidemic
-Does not focus on clinical intervention.
-Based on surveillance data.

A

Descriptive Epidemiology

37
Q
  • Aims to find cause and treatment.
    determinants – how and why?
  • Factors that influence observations of health and illness.
  • Must have observational data from descriptive studies or conduct observation
A

Analytic Epidemiology

38
Q

analytic studies

A

cohort

retrospective cohort study

39
Q
  • type of prospective, long term(longitudinal) and requires follow up
    *Prospective watch people for a while and see if disease dev
    -best estimate of disease incidence and risk
    Reduces bias because waiting to see if it happens
    study multiple affects
    Disadvantage: long follow up=attrition rate, large number of subjects, expensive, exposure factors may change, doesn’t work well with rare disease= not enough of them
A

Cohort study

Analytical

40
Q

– compare persons with the disease to those that do not, rigorous criteria to be able to participate, can be a control group
-questions the causality better, less data and resources

A

Retrospective cohort study

Analytical

41
Q

retrospective cohort

A

case control

cross sectional

42
Q

can estimate the risk, lesser number of subjects, less money, quicker, can investigate more than one exposure, best design for rare disease, best for disease with a relatively clear onset
Disadvantage: attrition rate

A

Case-control advantage
Retrospective cohort
Analytics

43
Q

correlation studies, relationship between the cause of disease, does not calculate the risk cause or incidence rate, can’t definitively substantiate the cause
Quick to plan and conduct, hypothesis is generated Ex: what causes disease
Address causality better
Disadvantage attrition rate

A

Cross-sectional:
Retrospective cohort
Analytical

44
Q

Can’t calculate the risk incidence or prevalence, not good for rare disease

A

Cross-sectional: Disadvantage

45
Q
  • investigator initiates a treatment or intervention to influence the risk for or course of disease, test whether interventions can prevent disease or improve health , person is randomly assigned to a particular group an intervention is applied and effects are measured
A

Experimental design

46
Q
  • evaluates the effectiveness of an intervention
    Best way to show causality
    Disadvantage: is it fair to withhold treatment if treatment truly appears to have effect, expensive in terms of time, personnel, facilities, and supplies
A

Clinical trial

Experimental

47
Q

experimental epidemiological studies

A

Clinical trial

. community trials

48
Q
  • investigation determines what the exposure or intervention will be, deal with health promotion and disease prevention rather than treatment of existing disease,
    intervention is usually undertaken on a large scale and unit of treatment is a region, or group rather than individuals
    -involve educational, programmatic, or policy interventions
  • best means for testing whether changes in knowledge or behavior, policy, programs or other mass interventions are effective
A

. community trials
advantage
experimental

49
Q
  • may take years for evident,
  • Comparable populations without similar interventions for comparative analysis are often difficulty to find
  • it is difficult and unethical to prevent the control from making use of generally available information=effectively making them different from the intervention
  • can be expensive, require a large staff, have complicated logistics, and need extensive communication about the study
A

. community trials disadvantage

experimental

50
Q

subjects are randomly assigned to groups, randomization is used, best way to show causality bc of the objective way in which the subjects are assigned, prospective and provide the clearest evidence of correct temporal sequence / double blind study

A

experimental group-

51
Q

avoids bias, treatments are assigned to pts so that all possible treatment assignments have a predetermined probability but neither subject nor investigator determines the actual assignment

A

Randomization:

experimental group

52
Q

-strong association between a potential risk factor and an outcome supports a causal hypothesis

A

Strength of association

causality

53
Q

causality

A

Strength of association

  • Consistency of findings
  • Biological plausibility
  • Demonstration of correct temporal sequence
  • Dose-response relationship
  • Specificity of the association
  • Experimental evidence
54
Q
  • repeated findings of an association with different study designs and in different populations strengthen a causal interference
A

Consistency of findings

causality

55
Q
  • demonstration of a physiological mechanism by which the risk factor acts to cause disease enhances the causal hypothesis, conversely an association that does not initially seem defensible may later be discovered to be so
A

Biological plausibility

causality

56
Q

for a risk factor to cause an outcome, it must precede the onset of the outcome

A

Demonstration of correct temporal sequence

causality

57
Q

the risk for developing an outcome should increase with increasing exposure (either in duration or quantity) to the risk factor of interest EX: more woman smokes during pregnancy the greater the risk for delivering a low birth weight infant

A

Dose-response relationship

causality

58
Q

-the presence of a one to one relationship between an agent and a disease, this criterion grows out of the infectious disease model in which it is more often though not always satisfied and is less applicable in chronic diseases

A

Specificity of the association

causality

59
Q
  • experimental designs provide the strongest epidemiologic evidence for causal association but they are not feasible or ethical to conduct for many risk factor disease associations
A

Experimental evidence

causality

60
Q

Epidemiologic triangle

A

Agent host environment

61
Q

fruit and veg wash well, certain med, exercise, vitamins, clean air, Things those are good…

A

B. Agents of Health

62
Q

Morbidity rates

A
  • incidence
  • attack
  • prevalence