Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Epidemiology > Exam 2 > Flashcards

Exam 2 Flashcards

1
Q

Ecologic Studies

A
  • unit: group level
  • can be used for making hypothesis
  • level of exposure for each individual is unknown
  • uses secondary data
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

ecologic comparison study

A

assess the correlation between exposure rates and disease rates among different groups over the same time period

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

ecologic trend study

A
  • correlation of changes in exposure with changes in disease within the same community, population, etc
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Ecologic Fallacy

A
  • occurs when incorrect inferences about the individual are made from group-level data.
  • observations made at the group level may not represent the exposure-disease relationship at the individual level
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

advantages and disadvantages of ecologic studies

A
  • advantages:
    • quick, simple, inexpensive, good for
      generating hypotheses when a disease is
      of unknown etiology
  • disadvantages:
    • ecological fallacy, imprecise measurement
      of exposure and disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

cross-sectional study

A
  • aka prevalence study
  • exposure and disease measures done at the individual level
  • Single period of observation
  • Exposure and disease histories are collected simultaneously.
  • Both probability and non-probability sampling are used
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

limitations of cross-sectional studies

A
  • Can’t really infer disease etiology
  • Doesn’t have incidence data
  • Can’t study low-prevalence diseases
  • Can’t determine the time between exposure and disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

cross-sectional survey strengths

A
  • Studies several associations at once
  • Takes a short period of time
  • Produce prevalence data
  • Biases due to observation (recall and interviewer bias) and loss to follow-up do not exist
  • Can provide evidence of the need for analytic epidemiologic study
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

types of data

A
  • nominal
  • ordinal
  • discrete
  • continous
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

nominal data

A
  • categorical: unordered categories
  • two levels: dichotomous
  • more than two levels: multichotomous
  • examples: sex, disease (yes, no), race, marital status, education status
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

ordinal data

A
  • categorical: ordering informative
  • examples: preference rating (agree, neutral, disagree)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

discrete data

A
  • quantitative: integers
  • example: number of cases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

continuous data

A
  • quantitative: values on a continuum
  • examples: dose of ionizing radiation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

crude vs age-adjusted rates

A
  • The crude rate is calculated without restrictions, such as by age or sex, or who is counted in the numerator or denominator.
  • These rates are limited if we try to compare them between subgroups of the population or over time because of confounding influences, such as differences in age distribution between groups.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

numerical methods

A
  • measures of central tendency
  • measures of dispersion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

measures of central tendency

A
  • mean: average of a set of values
  • median: middle number in a sorted list of numbers
  • mode: value that appears the most frequently in a data set
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

measures of dispersion

A
  • range
  • inter-quartile range
  • variance
  • standard deviation
  • coefficient of variation
  • empirical rule
  • Chebychev’s inequality
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

experimental studies

A
  • aka intervention studies
  • investigators influence the exposure of subjects
  • 2 types: controlled trials, community trials
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Within-group design

A
  • the outcome in a single-group is compared before and after the intervention
  • strengths: individual characteristics that confound an association are controlled
  • weakness: susceptible to confounding from time-related factors such as the media
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

controlled trial

A
  • unit of analysis is the individual
  • randomized controlled trial in a clinical setting is called a clinical trial
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

natural experiment

A
  • researchers don’t assign subjects unlike controlled
  • assignment into treatment and control is random like controlled experiments
  • researchers don’t design/ administer treatment unlike controlled
  • ex: John Snow cholera experiment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Between-group design

A
  • comparison between 2 outcomes observed in 2 or more groups of subjects that get different levels of intervention
23
Q

within-group design

A
  • compare the outcomes observed in a single group before and after the intervention
24
Q

Advantages of Randomized Controlled Clinical Trials

A
  • eliminate conscious bias due to physician or patient selection
  • averages out unconscious bias due to unknown factors
  • groups are “alike on average”
25
Q

Disadvantages of Randomized Controlled Clinical Trials

A
  • ethical issues
  • interferes with doctor-patient relationship
26
Q

single-blind study

A
  • subjects are blinded, but investigators are aware
  • ex: placebo controlled study
27
Q

double-blind study

A
  • subjects and investigators don’t know who is in what group
28
Q

triple-blind study

A
  • treatment and research approaches kept a secret from subject and investigators
  • analyses are done by a separate party removed from investigators
29
Q

Why are patients blinded?

A
  • patients try to get well/ please physicians
  • minimize potential bias from the placebo effect
30
Q

Placebo effect

A
  • effect of patient outcomes that may occur due to the expectation by a patient that the intervention will work
31
Q

problems with blinding patients

A
  • for non-drug studies like behavior change or surgeries it may be impossible or unethical to blind
  • may be problematic in drug studies where treatment has a characteristic side effect
32
Q

strengths of blinded randomized controlled clinical trials

A
  • shows cause and effect
  • faster and cheaper than observation studies
  • investigators can control exposure levels
  • only appropriate approach for some research questions
33
Q

weaknesses of blinded randomized controlled clinical trials

A
  • often costly in time and money
  • research questions are not suitable for experimental design due to ethics and rare outcomes
  • many research questions are not suitable to blinding
  • limited generalizability due to volunteers’ eligibility
34
Q

Phase 1 trial

A
  • unblinded, uncontrolled study with fewer than 30 patients
  • purpose is to determine safety
  • patient usually have advanced disease and tried other options
  • often undergo intense monitoring
35
Q

Phase 2 trial

A
  • up to ~50 people randomized blinded trials
  • tests: tolerability, safe dosage, side effects, how the body reacts to drug
  • evaluate which types of disease a treatment is effective against and most effective dosage
36
Q

Phase 3 trial

A
  • thousands of patients
  • random assignment of treatment
  • dosage and methods of administering are evaluated
37
Q

Phase 4 Trial

A
  • large study after FDA approval
  • assess the rate of serious side effects and explore further therapeutic uses
38
Q

what is a clinical trial?

A

research that test medical or health-related interventions

39
Q

what does phase 1 and 2 trials test?

A

the safety and effectiveness of the intervention

40
Q

what does a phase 3 trial test?

A

if the intervention works and is it helpful

41
Q

what is included in the experimental arm?

A

the group that gets the new treatment

42
Q

what is included in the control arm?

A

the group that gets the usual care

43
Q

what does randomized mean?

A

the decision to assign a subject to a group is done completely by chance

44
Q

informed consent

A

researcher provides all information related to the study to participants (ex: risks of treatment)

45
Q

when conducting research you should avoid what in terms of voluntary participation?

A

using pressure and coercion to get people to participate if they wouldn’t do it on their own

46
Q

what does honesty and integrity mean in terms of research ethics?

A

honestly reporting findings

47
Q

plagiarism

A

not asking for permission before using other materials

48
Q

in the 1930’s how many American’s were affected by syphilis?

A

1 out of 10

49
Q

what were the 2 key questions that healthcare professionals had during the syphilis experiment?

A
  • did late-stage syphilis warrant the risks of existing treatments
  • did the individual’s race affect how syphilis progressed
50
Q

what was the lie the syphilis study was based on?

A

participants were told they are getting free drugs and care when they weren’t

51
Q

What happened in Guatemala in the 1940’s?

A

non-infected individuals were infected with sexually transmitted infections

52
Q

when did the syphilis experiment end?

A

1972

53
Q

what was found at the end of syphilis experiment?

A

no evidence that race impacted how the disease progresses was found (found nothing)

Epidemiology (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions