General Concepts of Research

Question 1

types of quantitative study designs

Answer 1

interventional and observation

Question 2

interventional study design

Answer 2

considered “experimental”

forced allocation to study groups

investigator selects interventions (exposure)

Question 3

observational study design

Answer 3

considered “natural”

no forced allocation to study groups

researchers “observe” subject-elements occurring naturally or selected by individual (naturally or freely)

useful for unethical study designs using forced interventions

no designed to prove causation

Question 4

Interventional and Observation study design strength of evidence

Answer 4

Interventional Observational

• Phase 0 -Case Reports/Series
• Phase 1 -Ecological (not important)
• Phase 2 -Cross-Sectional
• Phase 3 -Case-Control
• Phase 4 -Cohort

*Increasing strength downward

Question 5

Research Evidence Pyramid

Answer 5

Systematic Reviews/Meta-Analyses
Interventional (Explanatory)/Pragmatic (Exploratory)
Cohort
Case-Control
Ecological (not important)
Case Series
Case Reports
Animal Research
In vitro (test-tube) research

Question 6

Research question

Answer 6

Purpose statement; formed as a question

Helps frame study intent and can direct researcher to selecting and developing an effective study design and methods to answer question

Question 7

Study design and methods selection is based on what?

Answer 7

• perspective of research question
• ability/desire of researcher to force group allocation and intervention (randomization)
• ethics of methodology selected
• efficiency and practicality
• costs
• Internal validity (validity of acquired information)
• external validity

Question 8

population

Answer 8

all individuals making up a common group; from which a sample can be obtained

Question 9

sample

Answer 9

a subset or portion of the full and complete population

Question 10

interventional study population is based on what?

Answer 10

research hypothesis

population of interest

inclusion and exclusion criteria (impacts external validity)

Question 11

observational study population is based on what?

Answer 11

research hypothesis

population of interest

Case and Control group OR Exposed and Non-Exposed group selection criteria (impacts external validity)

Question 12

Null hypothesis (Ho)

Answer 12

research perspective which states there will be no true difference between the groups being compared

Odds ratio is 1 between groups

Question 13

type I error

Answer 13

false positive

rejecting a true null hypothesis

Question 14

type II error

Answer 14

accepting (fail to reject) a false null hypothesis

Question 15

statistical-perspectives used in deciding to reject or not reject null hypothesis

Answer 15

• superiority: is the drug better than placebo? OR better than another drug?
• noninferiority: drug is not worse than the placebo
• equivalency: both drug and the placebo are the same

Question 16

prospective study

Answer 16

Don’t know outcome yet

groups are followed into future to assess for outcomes of interest and then groups are compared

used by all interventional studies and some observational studies

Question 17

retrospective study

Answer 17

outcome known at start of study

outcomes of interest have already occurred; researchers have goal of assessing past history of some activity (exposure/treatment)

Question 18

ambidirectional

Answer 18

uses retrospective design to assess past differences in occurrences of events (exposure or outcome), but also adds future data collected on additional outcomes prospectively from start of study

Question 19

probability samples

Answer 19

every element in population has a known (non-zero) probability of being included in sample

most common

Question 20

simple random sampling

Answer 20

type of probability sampling

assign random numbers, then take randomly-selected numbers to get desired sample size

OR

assign random numbers, then sequentially-list numbers and take desired sample size from top (or bottom) of listed numbers

Question 21

stratified simple random sampling

Answer 21

type of probability sampling

stratify sampling frame by desired characteristic (e.g. gender), then use simple random sampling to select desired sample size

Question 22

multi-stage random sampling

Answer 22

type of probability sampling

uses simple random sampling at multiple-stages towards patient selection

e.g. –> counties –> zip codes –> households –> individual

Question 23

non-probability sampling scheme

Answer 23

not a known probability

can produce selection bias

Question 24

quasi-systematic or convenience samples

Answer 24

not really completely random or fully probabilistic

decide on what fraction of population is to be sampled and how they will be sampled

e.g. all last name M-Z; all persons attending clinic every M/W/F for 6 months

Question 25

primary outcome

Answer 25

most important, key outcomes

main question used for developing study

Question 26

secondary/tertiary outcomes

Answer 26

less important outcomes but still valuable

used for possible future hypothesis generation

Question 27

single outcome

combined outcome

Answer 27

one type of outcome

single outcomes combined under one outcome

Question 28

internal validity

Answer 28

validity of methods inside study; answering question that’s asked

used standardized assessments that are accurate and reproducible

clinically applicable

Question 29

equipoise

Answer 29

genuine confidence that an intervention may be worthwhile (risk vs benefit) in order to use it in humans

e.g some don’t agree with use of placebo if a treatment is available, even though placebo can provide some benefit

Question 30

4 principles of bioethics

Answer 30

AUTONOMY: self-rule/self-determination; participants must decide for them-selves without outside influences (no coercion or financial manipulation); have full and complete understanding of risks vs benefits (consider language or education level)

BENEFICENCE: benefit to individual patient (not society); risks are justified by potential benefits

JUSTICE: equal and fair treatment regardless of patients characteristics (equipose); risks and benefits are equally distributed

NONMALEFICENCE: do no harm; researchers cannot withhold information, provide false information, or exhibit professional incompetence

Question 31

belmont report

Answer 31

issued by National Convention for Protection of Human Subjects of Biomedical and Behavioral Research

contains 3 principles: respect for persons (autonomy), beneficence, and justice

Question 32

consent

Answer 32

agreement to participate, based on being fully and completely informed as adults and mentally-capable individuals

Question 33

assent

Answer 33

agreement to participate, based on being fully and completely informed and mentally-capable individuals that are not able to give legal consent (minors)

Question 34

Institutional Review Board (IRB)

Answer 34

“ethics committee”

role is to protect human subjects from undue risk

all human subjects studies must be reviewed by an IRB prior to study initiation

Question 35

DHHS

Answer 35

Department of Health and Human Services

developed federal statutes that regulate IRB –> known as Common Federal Rule (CFR)

Question 36

OHRP

Answer 36

Office of Human Research Protections: agency that administers and enforces regulations by DHHS

Question 37

full board IRB eview

Answer 37

used for al intervention studies with more than minimal risk to patients

consists of entire board

Question 38

expedited IRB review

Answer 38

minimal-moderate risk (with/without patient identifiers)

consists of entire board

Question 39

exempt IRB review

Answer 39

low/no risk; no patient identifiers (anonymous); environmental studies; use of existing de-identified existing date/specimens

does not consist of entire board

Question 40

DSMB

Answer 40

Data Safety and Monitoring Board

reviews study data as study progresses to assess for risk/benefits and abiding of guidelines by IRB

can stop study early if one group receives more benefit or harm than the other group