Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Public Health > Overview of Epidemiological Studies > Flashcards

Overview of Epidemiological Studies Flashcards

1
Q

Lecture Objectives

A

1) recall the definitions and understand the assumptions underlying epidemiology and epidemiological research
2) understand the differences between experimental research and observational research
3) differentiate between association and causation
4) understand the purpose, characteristics, and measures of associations (if applicable) pertinent to each epidemiological study design
5) identify the advantages, disadvantages, and relative strength of each epidemiological study design

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Old definition of epidemiology

A

study of the distribution and determinants of disease frequency in man

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

New definition of epidemiology

A

the study of the distribution and determinants of health-related states or events in specified populations and the application of this study to control health problems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Distribution

A

Who, where, when “descriptive”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Determinants

A

What, why, how “analytical”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Population

A

inhabitants of a given area/region/group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Practical goal of epidemiology

A

to be used as a tool to improve the health conditions of the public

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Names of US population studies

A

Framingham Eye, Beaver Dam, Baltimore, Los Angeles Latino Eye, Chesapeake Bay Waterman , Wisconsin Epidemiologic study of diabetic retinopathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Names of Non-US population studies

A

Barbados, Blue Mountain, Rotterdam, Shihpau, Beijing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Incidence

A

the number of new problems or cases that develop in a population at risk during a given time period; often quantified as a rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Prevalence

A

the proportion of a given population with a problem at a designated time; quantified as a proportion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are examples of exposure?

A

actual exposure (toxic chemical or microorganism), a behavior or an individual attribute

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The exposure of interest may be associated with…

A

either an increased or a decreased occurrence of disease or other specified health outcome, and may relate to the environment, lifestyle or inherited characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are examples of outcome?

A

the disease state, event, behavior, or condition associated with health that is under investigation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are epidemiologic assumptions?

A

disease (and/or risk factors) don’t occur at random; disease is not randomly distributed throughout a population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are epidemiologic shortcomings?

A

difficulty in measuring exposure, separating causal contributions of exposure from other exposures, difficulty in assessing role of multiple small risks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the impractical goal of epidemiology aka the big epidemiological question?

A

does exposure A cause outcome B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are Hill’s causal criteria?

A

temporality, strength, biological gradient (dose-response), consistency (replication), specificity, plausibility, coherence (compatible), experimental evidence, analogy (alternate explanations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the ideal model?

A

counterfactual model

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How does the counterfactual model work?

A

ideally the population exposed/treated and the population not exposed/treated are the same subjects; you then follow-up and measure incidence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the real design?

A

the two populations are comparable subjects after adjustments, still follow-up and measure incidence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the overarching categories of epidemiological studies?

A

experimental and observational

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is an experimental study?

A

randomized controlled trial or individual or community

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the breakdown of observational studies?

A

analytic and descriptive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are analytic studies?
case-control and cohort
26
What are descriptive studies?
case report and ecological and cross-sectional
27
Experimental
exposure status assigned by researcher; generally described as clinical investigations
28
Observational
exposure status not assigned by researcher; primarily involves monitoring people in their natural environments
29
Characteristics of randomized controlled trial
experimental design; population is people w/o the outcome; assign treatment and check for outcome; subjects given standard treatment compared to subjects given experimental treatment; compare outcomes vs no outcome for each group
30
Randomized control trial of individual/community
measure the disease frequency or exposed/treated vs unexposed/control
31
Why is randomized control trial the gold standard?
random group assignment, blinded (preferably double), placebo group, treatment only difference between groups
32
Advantages of randomized control trials?
standard approach to test new treatments, prospective, exposure assigned
33
Disadvantages of randomized control trial?
time consuming, expensive, same effectivity in real world, non-compliance, ethical issue
34
Examples of random control trials
DRS, ETDRS, UK prospective DS, DCT, DRCR.net
35
What are optometry randomized control trials?
CITT and vision in preschoolers study
36
Analytic
used to help establish cause or risk factors for outcome (what, why, how)
37
Descriptive
identify patterns among cases and in populations by time, place, person (when, where, who)
38
What is a cohort study?
a forward or prospective study onset in the present with the future evaluated
39
Characteristics of a cohort study
observational and analytic; population is people without the outcome; start with exposure and check for outcome; subjects exposed compared to subjects not exposed; compare outcome vs no outcome for each group
40
Cohort advantages
comparison group, prospective, suitable for rare exposures, can examine a range of outcomes, temporality: exposure before outcome, establish relative risk, measure incidence
41
Cohort disadvantages
relatively expensive, time consuming (study subject drop-out, prolonged follow-up), not suitable for rare outcomes (disease)
42
What is a 2x2 contingency table?
compares exposure and outcome
43
What is an example of a cohort study?
Orinda vision screening study
44
What is a case-control study?
a backwards or retrospective study; onset in the present with analysis of the past
45
What are characteristics of the case-control study?
observational, analytic; population: people with the outcome and people without the outcome (control); start with outcome and check for exposure; subjects who have outcome compared to subjects who do not have outcome; compare exposed vs not exposed for each group
46
Advantages of case-control
comparison group, relatively inexpensive, quick, can study rare diseases, can test multiple hypotheses for a single outcome, generate exposure odds ratio
47
Disadvantages of case-control
retrospective, recall bias, no temporality: which came first, the outcome or the exposure
48
Eye related case control study
the lens opacities case-control study; risk factors for cataract
49
Cross-sectional characteristics
observational, descriptive; populationL people with the outcome and people without the outcome; exposure and outcome are measured simultaneously; measure and compare subjects with exposure and subjects with exposure and outcome
50
Advantages of cross-sectional study
relatively, inexpensive, quick, establish prevalence
51
Disadvantages of cross-sectional study
no cause and effect, no temporality, can miss rare exposures/outcomes (diseases), can miss outcomes (diseases) of short duration, not useful for rapidly emerging outcomes
52
Cross-sectional eye studies
framingham, baltimore, multi-ethnic pediatric eye disease, baltimore pediatric eye disease
53
Characteristics of ecological study
observational, descriptive; aka correlational study, analyzes groups/populations instead of individuals, try and determine relationship between exposure and outcome variables
54
Advantages of ecological studies
relatively inexpensive, quick (can sometimes use existing data), big picture (population trends, broad social processes)
55
Disadvantages of ecological studies
usually cannot establish causation, unable to control for confounding variable, ecological fallacy: can't extrapolate population data to individual subjects
56
Example of ecological eye related study
an ecologic study of trends in the prevalence of myopia in chinese adults in singapore born from the 1920s to 1980s
57
Characteristics of case report
observational, descriptive; case report: documents an unusual medical occurrence, case series: collections of individual case reports
58
Advantage of case report
first clue/early warning of a potential problem
59
Disadvantage of case report
anecdotal, non-scientific, the plural of anecdote is not data, no comparison group
60
Case report eye example
fusarium keratitis outbreak
61
T/F there are hybrid studies combining study types
true
62
What is the hierarchy of study strength from basic to scientific?
animal research, case series/case reports, case control study, cohort study, randomized controlled trial, systematic review, meta-analysis
63
What are grade A study types?
meta-analysis, systematic review, randomized clinical trial, diagnostic studies
64
What are grade B study types?
weak randomized clinical trial, cohort study, diagnostic study
65
What are grade C study types?
case control studies, diagnostic studies, studies of strong design, nonrandomized trials
66
What are grade D study types?
cross sectional studies, case reports/series, reviews, position papers, expert opinion, reasoning from principle
67
Example of action statement strength of evidence A
individuals should be advised by their health care providers of the risks of smoking and encouraged to quit smoking and/or seek smoking cessation assistance. Evidence grade: A, strong recommendation

Public Health (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions