Exam 2 Flashcards
(244 cards)
1
Q
Quantitative means _______ are used to represent data.
A
Numbers
2
Q
Qualitative means _______ are used to represent data.
A
Words
3
Q
A _____ _____ is used to depicts words used, showing the words used most often as the biggest.
A
Word cloud
4
Q
Quantitative studies can be divided into two categories, which are…
A
Interventional and Observational
5
Q
_________ study designs have forced allocation to study groups.
A
Interventional
6
Q
________ study designs do not have forced allocation into study groups. Investigators do not intervene.
A
Observational
7
Q
Interventional study designs are considered “experimental” and the investigator selects interventions (exposure). With this, there (IS/ IS NOT) researcher-forced group allocation. Randomization is utilized during this step.
A
IS
8
Q
Observational study designs considered “natural” and the researchers “observe” subject-elements occurring naturally or selected by individual (naturally or freely). With this, there (IS/ IS NOT) researcher-forced group allocation.
A
IS NOT
9
Q
Most observational study designs are not able to prove what?
A
Causation
10
Q
Interventional study designs go from Phase __ to Phase __ and (increase/decrease) evidence with each phase.
A
0; 4; Increase
11
Q
Observational study designs go in order from what to what? (5)
A
1) Case Reports/Series 2) Ecological 3) Cross-sectional*** 4) Case-control*** 5) Cohort***
12
Q
List the following observational studies in order from least to greatest evidence: a) Case-control b) Case Reports/Series c) Cohort d) Cross-sectional e) Ecological
A
b; e; d; a; c
13
Q
What are the 10 levels of the Research Evidence Pyramid in increasing strength of evidence?
A
1) In vitro (test-tube) research 2) Animal research 3) Case reports 4) Case series 5) Ecological 6) Cross-sectional 7) Case-control 8) Cohort 9) Intervenitonal (Exploratory) Trials OR Pragmatic (Explanatory) Trials 10) Systematic reviews OR Meta-analyses
14
Q
Which of the following study types provides the most strength of evidence? A. Case-control B. Pragmatic (Explanatory) Trials C. Cohort Study D. Meta-Analysis E. In-vitro Test Tube Research
A
D. Meta-Analysis
15
Q
Which of the following study types provides the least strength of evidence? A. Meta-Analysis B. Cross-Sectional Study C. Cohort Study D. Randomized Controlled Trial E. Case-control Study
A
B. Cross-Sectional Study
16
Q
Which of the following is considered the “gold standard” for clinical trial research? A. Systematic Review B. Case-Control Trial C. Randomized Controlled Trial D. In-vitro Test Tube Research E. Meta Analysis
A
C. Randomized Controlled Trial
17
Q
The Belmont Report summarizes ethical principles and guidelines for research involving human subjects. Which of the following is NOT a guiding principle of the Belmont Report? A. Justice B. Beneficence C. Respect for Persons D. Nonmaleficence
A
D. Nonmaleficence
18
Q
What statement helps frame study intent and can direct researcher to selecting and developing an effective study design to answer question?
A
“I wonder if….” (Research question)
19
Q
Study design selection is based on what 7 things?
A
1) Perspective of research question (Hypothesis) 2) Ability/Desire of researcher to force group allocation (randomization) 3) Ethics of methodology 4) Efficiency & Practicality (time/resource commitment) 5) Costs 6) Validity of acquired information (Internal Validity) 7) Applicability of acquired information to non-study patients (External Validity; Generalizability)
20
Q
This term refers to the individuals making up a common group from which a sample (smaller set) can be obtained, if desired.
A
Population
21
Q
This term refers to a subset or portion of the full, complete population (i.e., representatives). Useful when studying the complete population is not feasible.
A
Sample
22
Q
Study population selection is based on what? (3)
A
1) Research Hypothesis/Question 2) Population of Interest (most useful individuals to answer research question) 3) Inclusion and Exclusion selection criteria (Interventional studies) & Case/Control group OR Exposed/Non-exposed group selection criteria (Observational studies)
23
Q
This is a research perspective which states there will be NO (true) difference between the groups being compared. Researchers either reject or don’t reject this perspective, based on results (data analysis).
A
Null Hypothesis (H0)
24
Q
What are the 3 statistical perspecitves that can be taken by the researcher? How are their null hypotheses stated?
A
1) Superiority – “I’m not superior to…”
2) Noninferiority – “I am worse than…”
3) Equivalency – “I’m not equal to…”
25
This type of hypothesis is used when a research perspective states there will be a (true) difference between the groups being compared.
Alternative Hypothesis (H1)
26
A (Type I/ Type II) error is when a researcher did not accept the null hypothesis when they should have. A false-positive.
Type I
27
A (Type I/ Type II) error is when a researcher accepts the null hypothesis when they should have rejected it. A false negative.
Type II
28
This type of sampling scheme is the most common. Every element in the population has a known (non-zero) probability of being included in sample. (i.e., Picking one person in class, the denominator is known)
Probability samples
29
There are 6 types of probability sampling schemes, which are:
1) Simple Random sampling
2) Systematic Random sampling
3) Stratified Simple Random sampling
4) Stratified Disproportionate Random sampling
5) Multi-Stage Random sampling
6) Cluster Multi-Stage Random sampling
30
This type of sampling assigns random numbers, then take randomly-selected numbers to get desired sample size OR assigns random numbers, then sequentially-list numbers and take desired sample size from top (or bottom) of listed numbers
Simple Random sampling
31
This type of sampling is when random numbers are assigned, then randomly sort these random numbers, then select highest (or lowest) number, then systematically, by a pre-determined sampling-interval take every Nth numbers to get desired sample size.
Systematic Random sampling
32
This type of sampling is when we stratify the sampling frame by desired characteristic (i.e., Gender), then use Simple Random sampling to select desired sample size.
Stratified Simple Random sampling
33
This type of sampling disproportionately utilizes Stratified Simple random sampling when baseline population is not at the desired proportional percentages to the referent population. Stratified sample 'weighted' to return sample population back to baseline population (useful for 'over-sampling').
Stratified Disproportionate Random sampling
34
This type of sampling uses Simple Random sampling at multiple-stages towards patient selection.
(i.e., Regions/Counties (Primary Sampling Unit; PSU); City Blocks/Zip Codes (Secondary Sampling Unit; SSU); Clinic/Hospital/Household
Individual/Occurrence)
Multi-Stage Random sampling
35
This type of sampling is the same as Multi-Stage Random sampling but ALL 'elements' together (at any stage) are selected for inclusion.
(i.e., ALL clinics in a zip code; ALL households in a community)
Cluster Multi-Stage Random sampling
36
Non-probability sampling schemes are \_\_\_\_\_-\_\_\_\_\_\_\_ or __________ samples (not really, completely random or fully probabilistic). Decide on what fraction of populaion is to be sampled and how they will be sampled.
(i.e., All persons whose last name begins with M-Z;
All members of a professional business association;
All persons attending clinic every MWF for 6 months;
All persons referred by selected-peers (Concern: May introduce Selection Bias)
Quasi-systematic; Convenience
37
In human studies, the methodology of study deals with _________ or ________ \_\_\_\_\_\_\_\_.
Outcomes; Internal Validity
38
In the outcomes methodology of study, \_\_\_\_\_\_-oriented vs. \_\_\_\_\_\_\_-oriented outcomes are most important and useful. (Individual vs. Combined Outcomes)
Patient; Disease
39
In the internal validity methodology of study, the methods are (INSIDE/OUTSIDE) the study. Assessments (Measurements), scientifically-rigorous and standardized. Objective better than subjective assessments. Accurate and reproducible and scientifically.
INSIDE
40
In human studies, the study population selection is based on \_\_\_\_\_.
Ethics
41
This term refers to the genuine confidence that an intervention may be worthwhle (risk vs. benefit) in order to use it in humans.
Equipoise
42
The 4 Key Principle of Bioethics are...
1) Autonomy
2) Beneficence
3) Justice
4) Nonmaleficence
43
This key principle of bioethics is self-rule/self-determination. Participants must decide for ones-self, without outside influences (No coercion, reprisal, financial manipulation) and have full and complete understanding of the risks and benefits (No misinformation, incomplete information, or ineffectively-conveyed information at language or education level)
Autonomy
44
This key principle of bioethics is to benefit, or do good for, the patient (not society).
Beneficence
45
This key principle of bioethics is for equal and fair treament regardless of patient characteristics.
Justice
46
This key principle of bioethics is to do no harm. Researchers must not withold information, provide false information, or exhibit professional incompetence.
Nonmaleficence
47
In 1978, this was issued by the National Commission for Protection of Human Subjects of Biomedical and Behavioral Research and contains 3 guiding principles.
Belmont Report
48
The Belmont Report 3 guiding principles are...
1) Respect for persons
2) Beneficence
3) Justice
49
In the Belmont Report, this guiding principle states that research should be voluntary, subjects autonomous.
Respect for persons
50
In the Belmont Report, this guiding principle states that research risks are justified by potential benefits.
Beneficence
51
In the Belmont Report, this guiding principle states that risks and benefits of the research are equally distributed.
Justice
52
For humans to agree to participate in interventional studies, they must provide ______ (18 and older) or ______ (children and adolescents).
Consent; Assent
53
Agreement to participate, based on being fully and completely informed [given by mentally-capable individuals of legal consenting age (i.e., adults; age 18 in most states)]
Consent
54
Agreement to participate, based on being fully and completely informed, given by mentally-capable individuals NOT able to give legal consent (i.e., children and adolescents). Children or adults not capable of giving consent requires the consent of the parent or legal guardian and the _____ of the potential study subject.
Assent
55
This is who determines if study is ethical and safe. Its role is to protect human subjects from undue risk (research not complying with principles of bioethics). ALL human subject studies MUST be reviewed prior to study initiation.
Institutional Review Board (IRB)
(Referred to as the "Ethics Committee" internationally)
56
IRBs are regulated by Federal statutes (laws & regulations) developed by who?
Department of Health and Human Services (DHHS)
57
The rules the IRBs follow are referred to by CFR (Common Federal Rules). These apply to all studies funded by federal governemtn; standards also usually apply to studies reviewed by an IRB. The agency that administers and enforces the regulations is called...
Office of Human Research Protections (OHRP)
58
There are 3 levels of IRB review and differences, they are...
1) Full Board
2) Expedited
3) Exempt
59
This level of IRB review is used for ALL interventional trials with more than minimal risk to patients.
Full board
60
This level of IRB review is used for minimal risk and/or no patient identifiers.
Expedited
61
This level of IRB review is used for no patient identifiers, low/no risk, de-identified dataset analysis, environmental studies, use of existing data/specimens (de-identified).
Exempt
62
What are the main differences between the 3 levels of IRB review?
1) Number of members & time for committee review/approval
2) Level of detail to documentation needed for review
63
This semi-independent committee is not involved with the conduct of the study but charged with reviewing study data as study progresses, to assess for undue Risk/Benefit between groups. Pre-determined review periods (interim analyses); Can stop study early, for either overly-positive or overly-negative findings in one or more groups (compared to others).
Data Safety & Monitoring Board (DSMB)
64
This is at the top of the Research Evidence Pyramid and synthesizes LOTS of interventional studies into one "book report".
Systematic Reviews
65
This is at the top of the Research Evidence Pyramid and collects individual data from each study the puts all the data together into one "big study".
Meta-Analyses
66
Why is interventional studies higher up on the pyramid or research evidence?
Because it shows causation (Observational studies do NOT show causation)
67
Interventional studies increase in evidence from Phase 0 to 4. There are 4 things that generally differentiate each phase, and they are...
1) Purpose/Focus
2) Population studied (Healthy/Diseased)
3) Sample Size
4) Duration (within the diseased state
68
The higher the Phase # in interventional studies, the (HIGHER/LOWER) the population.
HIGHER
69
Phase 0 and 1 are the only studies that you will see ________ people in.
Healthy
70
In interventional studies, what is the stage prior to Phase 0 this is the 'bench' or animal research (prior to human investigation)?
Pre-Clinical
71
What is the very 1st phase at which any human could get a drug to test within a study?
Phase 0
72
What Phase of interventional studies is being described --
## Footnote
1) Assess drug-target actions and possibly pharmacokinetics in single or 'a few' doses (First-in-human use)
2) Healthy (or Diseased patients (oncology)) volunteers
3) Very small N (i.e., \<20)
4) Very short duration (i.e., a single dose to just a few days)
Phase 0 (Exploratory; Investiagtional New Drug)
73
What Phase of interventional studies is being described --
## Footnote
1) Assess safety/tolerance and pharmacokinetics of one or more dosages (First-in-human/Early-in-human use)
2) Healthy or Disease volunteers (depends on disease)
3) Small N (i.e., 20-80)
4) Short duration (i.e., just a few weeks)
Phase 1 (Investigational New Drug)
74
What Phase of interventional studies is being described --
## Footnote
1) Assess effectiveness (continues to assess safety/tolerability; expands on Phase 1 purpose)
2) Diseased volunteers (May have narrow inclusion criteria for isolation of effects)
3) Larger N (i.e., 100-300)
4) Short-to-Medium duration (i.e., a few weeks to a few months)
Phase 2 (Investigational New Drug)
75
What Phase of interventional studies is being described --
## Footnote
1) Assess effectiveness (continues to assess safety/tolerability)
2) Diseased volunteers (May expand inclusion criteria and comparison group(s) for delineation of effects. Various statistical-perspectives can be taken in studies: Superiority; Noninferiority; Equivalency)
3) Larger N (i.e., 500-3000)
4) Longer duration (i.e., a few months to a year +)
Phase 3 (Investigational New Drug; Indication/Population)
\*\*\*Last Phase before FDA approval (FDA requires 3-5 POSITIVE Phase 3 studies to approve drugs)
76
What Phase of interventional studies is being described --
## Footnote
1) Assess long-term safety, effectiveness, optimal use (risk/benefits)
2) Diseased volunteers (Expand use criteria (comorbidities/concomitant meds) for delineation of long-term safety/effects
3) Population (i.e., a few-hundred to a few-hundred-thousand)
4) Wide-range of durations (i.e., a few weeks to several years; ongoing; Interventional or Observational designs; Registries/Survey's also used in Observational design)
Phase 4 (post FDA-Approval)
\*\*\*After drug is on the market
77
What are the 2 advantages of using interventional studies over others?
1) Causation can be proven
2) Only designs used by FDA for approval process
78
What are the 4 disadvatnages of using interventional studies over others?
1) Cost
2) Complexity/Time
3) Ethical considerations (Risk vs. Benefit)
4) Generalizability (aka External Validity)
79
In an (EXPLORATORY/EXPLANATORY) study, it is very prescriptive and precise in its design. Study subjects can not switch drugs during this.
Exploratory
80
In an (EXPLORATORY/EXPLANATORY) study, there is much more flexibility for researcher, it's not so precise. Study subjects could switch drugs during the study.
Explanatory (Pragmatic)
81
This design of interventional studies is the most common. It divides (randomizes) subjects exclusively into greater than or equal to 2 groups. A single randomization process with no subsequent randomized divisions. Commonly used to test a single hypothesis (question) at a time.
Simple
82
This type of interventional study design divides (randomizes) subjects into greater than or equal to 2 groups and then further sub-divides (randomizes) each of the groups into greater than or equal to 2 additional sub-groups.
Factorial
83
Factorial interventional study designs are used to test multiple hypothese (questions) at the same time. With this there are 5 affects that occur, which are...
1) Improves efficiency for answering clinical questions
2) Increases study population sample size
3) Increases complexity
4) Increases risk to drop outs
5) May restrict generalizability of results
84
In this type of interventional study design, groups are simultaneously and exclusively mangaed. No switching of intervention groups after initial randomization.
Parallel
85
This type of interventional study design have groups serve as their own control by crossing over from one intervention to another during the study. This allows for a smaller total 'N' (sample size) because each patient can contribute additional data.
Cross-over (aka Self-Control)
86
What are all of the possible study designs that can occur between simple, factorial, parallel, and cross-over designs.
Simple Parallel
Simple Cross-over
Factorial Parallel
Factorial Cross-over
87
In cross-over study designs, there must a \_\_\_\_\_-\_\_\_\_\_ to allow time for the first drug to get out the study subject's system.
Wash-out
88
This is a phase done before a study starts. The study subjects are given placebo pills without knowing for a certain amount of time to determine a "new" base-line of disease (standardization).
Lead-In (Run-In) Phase
89
What are the advantages of having a lead-in phase for studies? (3)
1) Can assess study subject's protocol compliance
2) Can 'wash-out' existing medication
3) Can determine amount of placebo-effect (new baseline)
90
What are the 6 disadvantages of using a cross-over study design?
1) Only suitable for long-term conditions which aren't curable or which treatment gives short-term relief
2) Duration of study for each subject is longer
3) Carry-over effects during cross-over (wash-out required; which prolongs study duration)
4) Treatment-by-Period interaction (differences in effects of treatments during different time periods)
5) Smaller N requirement only applicable if within-subjects variation less than between-subjects variation
6) Complexity in data analysis
91
In interventional studies, there can be certain kinds of outcomes or endpoints. What kind are the most important, or key outcomes that are answering the main research question (hypothesis) used for developing/conducting the study?
Primary
92
In interventional studies, this outcome/endpoint is of lesser importance yet still valuable. It leaves a possibility for future hypothesis generation.
Secondary/Tertiary/etc.
93
In interventional studies, this outcome/endpoint combines multiple endpoints into a single outcome. It could be considered the primary outcome, and if so, then secondary outcomes may be the individual outcome elements from it.
Composite
94
These outcomes/endpoints in an interventional study are the most clinically relevant. They look at death; stroke or myocardial infarction; hospitalization; preventing the need for dialysis. These are considered (PATIENT/DISEASE) oriented endpoints.
Patient-Oriented
95
This outcome/endpoint for interventional studies looks at the more indirect risk. For example, it considers blood pressure (for risk of stroke); cholesterol (for risk of heart attack); change in SCr (for worsening renal function). These are called (PATIENT/DISEASE) oriented endpoints.
Disease-Oriented
96
In interventional studies, this type of group allocation occurs when subjects do NOT have an equal probability of being selected or assigned to each intervention group. For example, patients attending morning clinic assigned to group 1, patients attending afternoon clinic assigned to group 2.
Non-random
97
In interventional studies, this type of group allocation is most commonly utilized and occurs when subject DO have and equal probability of being assigned to each intervention group. For example, a random-number generating program is used to assign groups.
Random
98
What is the clue word in the stem of a study that signals this study is and interventional study?
Randomization
99
The purpose of __________ is to make groups as equal as possible, based on known and unknown important factors (confounders). It attempts to reduce systematic differences (bias) between groups which could impact results/outcomes.
Randomization
100
This is customarily used to show group characteristics and their equality within an article. Equality of groups is not guaranteed.
Table 1
101
Documentation of equality of groups (effectiveness of randomization process) reported in 1-of-several locales:
p-values shown in ______ format
p-values not shown but text-statement given in key of \_\_\_\_\_\_
p-values not shown but text-statment given in \_\_\_\_\_
Table; Table; Article
102
Randomization (IS/IS NOT) used in observational studies.
Is not
103
There are 3 forms of randomization, which are...
1) Simple
2) Blocked
3) Stratified
104
This form of randomization gives equal probability for allocation within one of the study groups.
Simple
105
This form of randomization ensures balance within each intervention group. It guarantees groups will be relatively equal in number.
Blocked
106
This form of randomization ensures balance with known confounding variables. They can also pre-select levels to be balanced within each interfering factor (confounder). Examples: gener, age, disease severity/duration, comorbidities.
Stratified
107
In interventional studies, often the study subjects and investigators must be masked (to avoid bias). This type of masking is when study subjects are not informed on which intervention (treatment) group they are in, yet investigators are permitted to know.
Single-blind
108
In interventional studies, often the study subjects and investigators must be masked (to avoid bias). In this form of masking, neither investigators nor study subjects are informed which intervention (treatment) group subjects are in (post-study survey's can be used to assess adequacy of blinding).
Double-blinding
109
In interventional studies, often the study subjects and investigators must be masked (to avoid bias). In this type of masking, study subjects and researcher know what intervention is being received.
Open-Label (unmasked/unblinded)
110
In interventional studies, often the study subjects and investigators must be masked (to avoid bias). In this type of masking, inert treatments are made to look identical in all aspects to the active treatments.
Placebo ("Dummy" therapy)
111
In interventional studies, often the study subjects and investigators must be masked (to avoid bias). This type of masking is the same as placebo, however it uses more than 1 placebo.
Double-Dummy
112
In interventional studies, often the study subjects and investigators must be masked (to avoid bias). This type of masking occurs when the improvement in condition by power of suggestion of being "treated" (improvement can be as large as 30-50%).
Placebo-effect
113
In interventional studies, often the study subjects and investigators must be masked (to avoid bias). In this type of masking, the study subject change their behavior solely due to awareness of being studied/observed.
Hawthorne-effect
114
Post-hoc sub-group analyses (ARE/ARE NOT) accepted as apporpiate, by most, when they are not prospectively planned (data-dredging or fishing). This can result in reduced power and increases the risk of Type 2 error.
Are not
115
Post-hoc sub-group analyses (ARE/ARE NOT) accepted as appropriate, by most, when it is prospectively planned, or performed for hypothesis generation and development of future studies.
Are
116
When managing drop-outs/lost-to-follow-ups, this is the technique used that is the most conservative and best way to reduce bias. It keeps all of the subject's data in the group they were assigned, regardless of them finishing the study or not.
Intent-to-treat
117
The 3 reasons why intent-to-treat is best to use for managing drop-outs are...
1) Preserves randomization process
2) Preserves baseline characteristics and group balance at baseline which controls for known and unknown confounders
3) Maintains statistical power (original sample size)
118
This technique used for managing drop-outs/lost-to-follow-ups is to just ignore them and only include data from subjects that were compliant.
Per-protocol (Efficacy-analysis)
119
This technique used for drop-outs/lost-to-follow-ups will ignore group assignments. It allows subjects to switch groups and be evaluated in the group they moved to, end in, or stay in the most.
As-Treated
120
Using the Per-Protocol technique for drop-outs/lost-to-follow-ups, will result in reduced __________ (external validity).
Generalizability
121
What are methods used to assess adherence (compliance)?
1) Drug levels
2) Pill counts at each visit
3) Bottle counter-tops
122
What are methods of improving adherence (compliance)?
1) Frequent follow-up visits
2) Treatment alarms
3) Dosage containers (Medication blister packs)
123
A case-control study is a type of (INTERVENTIONAL/OBSERVATIONAL) study.
Observational
124
This is a type of observational study allowing researchers to be a passive observer of natural events occurring in individuals with the disease/condition of interest (cases) who are compared with people who do not have the condition of interest (controls).
Case-control study
125
Case-control studies are useful when studying a rare disease or an outbreak. Group-assignments are based on ________ status.
Disease
126
In an observational study, when we have more than we need then we will _______ select people.
Randomly
127
T/F. When the stem of a study says "randomly-selected" it automatically means observational.
False. It could an interventional study as well.
128
T/F. When the study stem says "randomization" then it is always an interventional study.
True
129
What are 4 reasons you should choose a case-control study design?
1) Unable to force group allocation (randomization) because it's unethical or not feasible
2) Limited resources
3) The disease of interest is rare and little is known about its associations/causes
4) Prospective exposure data is difficult/expensive to get and/or very time inappropriate
130
When an exposure occurs before the outcome, that is considered (PROSPECTIVE/RETROSPECTIVE).
Prospective
131
When an outcome is known before the exposure, it is considered (PROSPECTIVE/RETROSPECTIVE).
Retrospective
132
Interventional studies are (PROSPECTIVE/RETROSPECTIVE) and case-control studies are (PROSPECTIVE/RETROSPECTIVE).
Prospective; Retrospective
133
List the strengths of a case-control study (6)...
1) Good for assessing multiple exposures of one outcome
2) Useful when diseases are rare
3) Useful in determining associations (not causation)
4) Less expensive (money/time)
5) Useful when ethical issues limit interv. studies
6) Useful when disease has a long induction/latent period
134
What are weaknesses of a case-control study? (5)
1) Can't demonstrate causation
2) Can be impacted by unassessed confounders
3) Retrospective
4) Can be impacted by various biases (Selection/Recall)
5) Limited by available data
135
The most difficult part in a case-control study is selecting the (CASE/CONTROL).
Control
136
When selecting a control, we want to make sure they are as equal as possible to the cases (minus disease) and DO NOT look at the ________ prior to choosing controls.
Exposure
137
In choosing for controls, if exposure is looked at prior to choosing them and then exposure has no effect, the odds will be exactly the same for both case and control groups, resulting in an OR of 1 meaning there (IS/IS NOT) a difference between groups.
Is not
138
A study was done in 1980 over heat-strokes in a heat wave in Missouri. A study was done on 156 (including 73 fatal cases) of the heat-stroke cases. Neighborhood members were found to be controls from the source population. In order to qualify they hade to be the same (GENDER/AGE) and plus/minus 5 years of age (except if the case was 70 then the control could be greater or equal to 65). They went door-to-door using a standardized (pre-defined) systematic 'control-search' pattern (goal was 3 controls per 1 case).
Gender
139
Outbreak-sources of controls are those that participated in (THE SAME/DIFFERENT) event(s) (i.e., picnic/convention).
The same
140
An individual can actually function as both an _______ individual and an ________ individual in the same study. For example, this can be associated with an outbreak investigation with multiple exposures (foodborne) OR in a case-crossover design.
Exposed; Unexposed
141
A \_\_\_\_\_\_-\_\_\_\_\_\_ design is a situation of a brief (acute) change in risk of the outcome in interest (hazard period). A subject can be their own control during other times they don't have an acute change in risk.
Case-crossover
142
These are case-control studies conducted after, or out of, a prospective previous study-type (cohort or interventional study). The subjects in cohort study, ultimately developing disease/outcome, are defined as cases for the subsequent case-control study. (Used to evaluate other exposures)
Nested case-control study
143
There are 3 selections of controls used for Nested Case-Control studies, which are...
1) Survivor sampling
2) Base sampling
3) Risk-set sampling
144
This type of control selection from nested case-control studies are a sample of non-diseased individuals **at the end** of the previous study period.
Survivor sampling
145
This type of control selection used for Nested Case-Control studies use a sample of non-diseased individuals **at the start** of the previous study period.
Base sampling
146
This type of control selection used for Nested Case-Control studies is for a sample of non-diseased individuals **during the study** period at the same time when case was diagnosed (during previous study).
Risk-Set sampling
147
What are the 2 common biases related with case-control studies?
Recall bias
Selection bias
148
This type of bias is related to the way subjects are chosen for the study (usually more of a concern for control selection).
Selection bias
149
This type of bias is related to the amount/specificity that cases or controls remember past events differently. More common that cases are more likely to remember past exposures and levels of exposures (or their timing).
Recall bias
150
In some studies, cases are _______ to controls (in a 1:1 or higher ratio). There can be individual matching or group matching.
Matched
151
This type of matching is based on specific patient-based characteristics. Useful for controlling confounding characteristics.
Individual matching
152
This type of matching is when a proportion of cases and proportion of controls with identical characteristics are matched. It requires cases to be selected first. (i.e., 41% of cases are male, so 41% of controls are male)
Group matching
153
DO NOT match on anything that might be a ____ factor (i.e., do not match based on exposures).
Risk
154
This type of study is an observational study allowing the researcher to be a passive observer of natural events occurring in naturally exposed and unexposed (comparison) groups. The group allocation is based on exposure status OR group membership (something in common).
Cohort study
155
Cohort studies are useful when studying a _____ exposure.
Rare
156
Cohort studies are also known as _________ or _________ studies.
Incidence; Longitudinal
157
A cohort study can be conducted in a prospective, retrospective, or __________ fashion.
Ambidirectional
158
In a (PROSPECTIVE/RETROSPECTIVE) cohort study, the exposure group is selected on the basis of a past or current exposure and both groups (exposed and non-exposed) are followed into the future to assess for outcome(s) of interest (which has yet to occur), and then compared.
Prospective
159
A prospective cohort study is considered the only observation study that is able to prove \_\_\_\_\_\_\_\_\_.
Causation
160
In a (PROSPECTIVE/RETROSPECTIVE) cohort study, at the start both exposure and outcome of interest have already occurred, but groups are still allocated on past history of exposure.
Retrospective
161
In a retrospective cohort study, the study "starts" at time of exposure (historically) and follow forward to the point of outcome occurrence (known) in the present. The ________ still has to occur **before** outcome of interest and group allocation is based on this. Not disease status.
Exposure
162
This type of cohort study uses retrospective design to assess past differences (up to present), but also adds future data collected on additional outcomes prospectively from start of study.
Ambidirectional
163
A ______ cohort is a group of individuals assembled based on being born in a geographic region in a given time period. (i.e., Everyone born in KC city limits in 2014)
Birth
164
An ________ cohort is a group of individuals assembled at a given point based on some common factor. (i.e., Where people live or where they work, or something they have in common. Useful for single-group assessment for incidence rate determination. Like a single health-care system, or single payer of health-care coverage)
Inception
165
A _______ cohort is a group of individuals assembled based on some common exposure (Frequency connected to environmental or other one-time events). An example of this is 9/11.
Exposure
166
Cohort sizes may or may not change over time. There are 3 types of cohorts based on size, which are...
1) Fixed Cohort
2) Closed Cohort
3) Open (Dynamic) Cohort
167
A ______ cohort is a cohort derived from an irrevocable event which can't gain members but **CAN** have loss-to-follow-ups.
Fixed
168
A _______ cohort is cohort derived from an irrevocable event which can't gain members but **CANNOT** have loss-to-follow-ups.
Closed
169
A _______ cohort is a cohort with new additions and some loss-to-follow-ups. The cohort can increase or decrease over time, as people immigrate or emigrate in and out of the population (cohort) being studied.
Open (Dynamic)
170
In a cohort study, selecting the (EXPOSED/UNEXPOSED) is the easier part. Subjects are allocated based on pre-defined criteria of ________ (scientifically and consistently determined).
Exposed; Exposure
171
In a cohort study, the measure of association generally used or looked at is ____ ratio/Relative \_\_\_\_.
Risk; Risk
172
In a cohort study, the ______ group is selected by trying to make it as close as possible (coming from the same cohort/population yet not exposed).
Unexposed
173
If exposure truly has no effect (in cohort), then risk will be exactly the same for both groups and RR will be ____ (no difference).
One
174
In a cohort study, the unexposed group can come (broadly) from 3 sources, which are...
1) Internal (within cohort)
2) General population
3) Comparison cohort
175
When choosing the unexposed group in a cohort study, _______ subjects are the best if feasible because they come from the same cohort yet are unexposed. (Most similar)
Internal
176
When choosing the unexposed group in a cohort study internally, if there are only ______ of exposure you may have to use the lowest exposure group as comparator (if there is not a 'no exposure' group internally available).
Levels
177
When choosing the unexposed group in a cohort study, this option is used as a second choice when the best-possible comparison group (internal) is not realistically possible (i.e., when everyone is exposed; or the exposure subjects were drawn from the general population)
General Population
178
When choosing the unexposed group for a cohort study, this is the least acceptable group (but still can be utilized). We are simply attempting to match groups as close as possible on numerous personal characteristics (can't control for other potentially harmful exposures; also causing disease).
Comparison Cohort
179
List the strengths of using cohort studies (7)...
1) Good for assessing multiple outcomes of ONE exposure
2) Useful when exposure are rare
3) Useful in calculating Risk and RR's
4) Less expensive than interventional trials
5) Good when ethical issues limit interventional use
6) Good for long induction/latent periods (Retrospective)
7) Able to represent "Temporality" (Prospective)
180
List the weaknesses of a cohort study (7)...
1) Can't prove causation (Retrospective)
2) Hard to control for other plausible exposures
3) Retrospective; can't control for other exposures
4) Not good for long induction/latent periods (Prospective)
5) Can be impacted by unassessed confounders
6) Biases can impact (Selection and Recall)
7) Limited by available data
181
List the advantages of a PROSPECTIVE cohort study (5)...
1) Can obtain greater amount of study-important infrom from patients
2) Follow-up/Tracking of patients is easier
3) Better at giving answer to "Temporality"
4) May look at multiple outcomes for single exposure
5) Can calculate incidence and incidence rates
182
List the disadvantages of a PROSPECTIVE cohort study (4)...
1) Time, expense, and lost-to-follow-ups
2) Not efficient for rare diseases
3) Not suited for long induction/latency conditions
4) Exposure (or its "amount") may change over time
183
List the advantages of RETROSPECTIVE cohort studies (4)...
1) Best for long induction/latency conditions
2) Able to study rare conditions
3) Useful if the data already exists
4) Saves time and money compared to Prospective
184
List the disadvantage of RETROSPECTIVE cohort studies (4)...
1) Requires access to charts, databases, records, etc.
2) "Information" may not factor in or control for other exposures over time
3) Patients may not be available for interview if missing data
4) Exposure (or its "amount") may have changed over time
185
In a cohort study, _______ is a way to strive to make groups as equal as possible on known/potential confounders. Can do this on a 1:1 ratio or even higher, 1:5 ratio (exposed to unexposed).
Matching
186
What are the 2 key biases with cohort studies?
1) Healthy-worker effect
2) Selection bias
187
This type of bias within a cohort, deals with a study subject being healthy and working (even if exposed) but if they're too ill to work (due to the exposure) they may be unemployed (now part of non-working general population).
Healthy-worker effect
188
This type of bias within a cohort, deals with how the exposure status is defined/determined (less of an issue with exposure status vs. confirming non-exposure).
Selection bias
189
This is the only case-control design able to adequately attempt to address the issue of temporality.
Case-crossover
190
Cross-sectional studies are a ___________ study. It looks at what is occuring at a point in time or time-frame across a large population.
Prevalence
191
This type of observational study focuses simultaneously on disease and population characteristic, including exposures, health status, health-care utilization, etc.
Cross-sectional study
192
Cross-sectional studies seek __________ (not causation). They generate and test _________ (possible associations), and by repetition in different time periods, they can be used to measure \_\_\_\_\_\_\_/\_\_\_\_\_\_\_\_ (not in same patients).
Associations; Hypotheses; Change/trends
193
Many cross-sectional studies are large-scale national ________ or _________ capturing different aspects of the 'population'.
Surveys; Databases
194
There are 2 cross-sectional study approaches, which are...
1) Collect data on each member of the population
2) Take a sample of the population and draw inferences to the remainder (generalizable)
195
This type of cross-sectional study approach is more frequently used in city/state-level evaluations, if data is already tracked (ongoing collection).
Collect data on each member of population
196
This type of cross-sectional study approach is more frequently used, and look at U.S.-level data.
Take sample of population and draw inferences to the rest (generalizable)
197
What are the 2 broad approaches to collecting study data/information in cross-sectional studies?
1) Questionnaires/Surveys
2) Physical assessments
198
What are the strengths of using a cross-sectional study? (5)
1) Quicker and easier for the researcher when using data already collected
2) Less expensive for researcher than any prospective study
3) Can analyze like case-control or cohort study
4) Useful for estimating prevalance rates
5) Useful for answering research questions about a ton of exposures and diseases using same data
199
What are the weaknesses of using a cross-sectional study? (4)
1) Prevalent cases may represent survivors
2) Difficult to study diseases of low frequency
3) Unable to generate incidence rates
4) Problems in determining temporal relationship of presumed cause and effect
200
There are 5 examples of cross-sectional studies we looked at, which are...
NHANES
NHIS
NAMCS
NHCS
BRFSS
201
This type of survey assesses the health and nutritional status of adults and children. It combines interviews and physical exams (medical, dental, lab tests, etc.)
National Health and Nutrition Examination Survey
NHANES
202
This type of survey is a principal source of information on the health of the civilian, non-institutionalized population. (aka Non-military and Non-hospitalized). Data are collected through a personal household interview. Consists of a set of core questions that remain unchanged and a set of supplements used to respond to public health data needs as they arise. (All ages used)
National Health Interview Survey
NHIS
203
This type of survey is a national survey designed to meet the need for objective, reliable information about the provision and use of ambulatory medical care services in the United States. It's based on a sample of visits to non-federal, non-institutional (office-based) physicians primarily engaged in direct patient care.
National Ambulatory Medical Care Survey
NAMCS
204
This type of survey is a combined national survey designed to describe national patters of healthcare delivery in non-federal hospital-based settings, including discharges from inpatient departments and institutions, and visits to emergency departments, outpatient departments and ambulatory surgery centers. (Integrates NHDS, NHAMCS, and DAWN)
National Hospital Care Survey
NHCS
205
This type of survey is a state-based system of telephone health surveys that collects information on health risk behaviors, preventive health practices, and health care access primarily related to chronic disease and injury. Monthly data collection in all 50 states (and US territories). Only adults (18 or older) interviewed by telephone. Youth version conducted by questionnaire in schools.
Behavior Risk Factor Surveillance System
BRFSS
206
What are the 2 questions a patient should ask their physician when a medical screening test is recommended?
1) How **accurate** is the screening test you are about to recommend for me?
2) When the test results are announced, how **confident** will you be in your prediction of whether I do or don't have the disease?
207
A _____ \_\_\_\_\_ test correctly reports a positive result in a patient that acutally DOES have the disease.
True Positive (TP)
208
A _____ \_\_\_\_\_ test correctly reports a negative result in a patient that acutally DOES NOT have the disease.
True Negative (TN)
209
True Positives live in box ___ and True Negatives live in box ___ on the 2x2 table.
A; D
210
A _____ \_\_\_\_\_ test incorrectly reports a positive result in a patient that actually DOES NOT have the disease.
False Positive (FP)
211
A ______ \_\_\_\_\_\_ test incorrectly reports a negative result in a patient that actually DOES have the disease.
False Negative (FN)
212
False Negatives live in box ___ and False Positives live in box ___ on the 2x2 table.
C; B
213
If we want to know how **accurate** a screening test is, we use _______ and \_\_\_\_\_\_\_.
Sensitivity
Specificity
214
Sensitivity and specificity screening is done on people we KNOW are _______ or not \_\_\_\_\_\_\_\_.
Diseased; Diseased
215
\_\_\_\_\_\_\_\_ is how well a test can detect the presence of disease when in fact disease is present. This number is a proportion (%).
Sensitivity
216
A highly sensitive test has a low false (NEGATIVE/POSITIVE) rate.
Negative
217
Sensitivity can be calculated by...
TP / (TP+FN) x 100%
[A / (A+C) x 100%]
218
\_\_\_\_\_\_\_\_ is how well a test can detect absence of disease when in fact the disease is absent. This number is a proportion (%).
Specificity
219
A highly specific test has a low false (POSITIVE/NEGATIVE) rate.
Positive
220
Specificity can be calculated by...
TN / (TN+FP) x 100%
[D / (B+D) x 100%]
221
When a patient asks how confident you are in the prediction of having disease or not, you use ______ \_\_\_\_\_ _____ and _____ \_\_\_\_\_ \_\_\_\_\_.
Positive Predictive Value
Negative Predictive Value
222
A ______ \_\_\_\_\_\_ ______ tells how accurately a positive test predicts the presence of disease. This number is a proportion (%).
Positive Predictive Value (PPV)
223
Positive Predictive Value (PPV) can be calculated by...
TP / (TP+FP) x 100%
[A / (A+B) x 100%]
224
\_\_\_\_\_\_ ______ \_\_\_\_\_\_ says how accurately a negative test predicts the absence of disease. This number is a proportion (%).
Negative Predictive Value (NPV)
225
Negative Predictive Value (NPV) can be calculated by...
TN / (TN+FN) x 100%
[D / (C+D) x 100%]
226
Why does sensitivity and specificity not change within two different populations with different prevalence?
Because the test itself does not change.
227
As you approach 100% prevalence of a disease, (NPV/PPV) goes up and (NPV/PPV) goes down.
PPV; NPV
228
If sensitivity or specificity is not 100, then what causes it to not be 100?
False positives
False negatives
229
This is a proportion (%) of total screenings that a patient is correctly identified as either having a disease (TP) or not having a disease (TN) with either a positive or negative test, respectively.
Diagnostic Accuracy (DA)
230
Diagnostic Accuracy (DA) can be calculated by...
(TP+TN / (TP+FP+FN+TN) x 100%
[(A+D) / (A+B+C+D) x 100%]
231
\_\_\_\_\_\_\_ _______ is the ratio of the probability (%) of a 'given test result' (positive or negative) for a person with disease (numerator always) divided by the probability (%) of the same test result (positive or negative) for a person without disease (denominator always).
Likelihood Ratio
232
\_\_\_\_\_\_\_ ______ \_\_\_\_\_\_\_ is the probability (%) of a positive test in the presence of disease divided by the probability (%) of a positive test in the absence of disease.
Likelihood Ratio Positive (LR+)
233
LR+ can be calculated by...
Sensitivity / (1-Specificity)
[(A/(A+C)) / (B/(B+D))]
234
\_\_\_\_\_\_\_ _______ \_\_\_\_\_\_ is the probability (%) of a negative test in the presence of disease divided by the probability (%) of a negative test in the absence of disease.
Likelihood Ratio Negative (LR-)
235
LR- can be calculated by...
(1-Sensitivity) / Specificity
[(C/(A+C)) / (D/(B+D))]
236
LR+ should be greater than ____ to demonstrate the test is most beneficial and LR- should less than ____ to demonstrate the test is most beneficial.
10; 0.1
237
The ability to accurately discern between those that DO and those that DO NOT have the disease is called \_\_\_\_\_\_\_\_.
Validity
238
Validity is analogous to ________ (in finding/reporting the truth).
Precision
239
(EXTERNAL/INTERNAL) validity is the extent to which results accurately reflect what was being assessed (true situation of study population).
Internal
240
(EXTERNAL/INTERNAL) validity is the extent to which results are applicable to other populations (not included in the original study; also known as "Generalizability").
External
241
\_\_\_\_\_\_\_\_ is the ability of a test to give the same result on repeated uses.
Reliability
242
Reproducibility/Consistency is analogous to \_\_\_\_\_\_\_\_.
Reliability
243
\*\*A ______ test is ALWAYS reliable, yet a reliable test is NOT ALWAYS \_\_\_\_\_\_.\*\*
Valid; Valid
244
Study "multiple cutoff values" slide for 5 minutes.
