Methodology & Study Design Flashcards
2 categories of general study design
qualitative
quanitative
2 categories of numerical studies
quantitative studies
interventional or observational
random or forced allocation to study groups
interventional study
no random or forced allocation to study groups
observational study
types of experimental studies
pre-clinical/animal studies
phase 0 - 4
in general observational studies cannot ______ ?
prove causality
interventional can
types of observational studies in order of increasing evidence
case report/series ecological cross-sectional case-control cohort
what is the most useful and appropriate study design?
it depends
the best study design is the one that best answers the primary question of the research hypothesis
what criteria are considered when choosing study design? (7)
perspective of hypothesis ability to randomize ethics practicality/efficiency cost validity of data applicability (generalizability)
population vs. study population
study population = sample size
3 perspectives taken by the null hypothesis
superiority
noninferiority
equalness
types of sampling schemes
probability samples
non-probability sampling
types of probability sampling (6)
simple random sampling systematic rs stratified simple rs stratified disproportionate rs multistage rs cluster multistage rs
type of non-probability sampling
quasi systematic or convenience sampling
random number generator use
simple random sampling
sampling by choosing every 5th number given by a random number generator
systematic random sampling
sampling that stratifies by desired characteristics then uses a random number generator
stratified simple random sampling
use of stratified simple random sampling on a population that does not have the desired proportional percentages
stratified disproportionate random sampling
weighted sampling
simple random sampling at multiple stages
multi-stage random sampling
simple random sampling at multiple stages within a cluster of the desired element
cluster multi-stage random sampling
some known or unknown order to the sampling which can introduce bias
quasi systematic sampling also called convenience sampling
what does external validity represent?
the ability to generalize the findings to the population
define equipoise
genuine confidence that an intervention may be worthwhile in order to use it in humans
confidence that the benefits outweigh the risks
what is the difference between consent and assent?
consent you can give yourself
assent is given by a legal guardian
in both ways you must be mentally capable of knowing what you are being enrolled in
what must be met in order for a study to begin? what subject does this represent?
principles of bioethics
ethics
principles of bioethics
autonomy
beneficence
justice
Nonmaleficence
define autonomy principle of bioethics
participants must be able to decide for themselves and must be able to understand the risks and benefits
w/o influence, coercion, financial manipulation, etc.
define beneficence principle of bioethics
the intervention must be to improve the individual not society
define justice principle of bioethics
equal and fair treatment regardless of patient characteristics
ex. gender, age, race, etc.
define Nonmaleficence principle of bioethics
do no harm
3 things the researcher must not do…..according to the Nonmaleficence principle of bioethics
withhold info from patient
provide false info to patient
exhibit professional incompetence
issuing of the Belmont report
1978
issued by the national commission for protection of human subjects of biomedical and behavioral research
the Belmont report
3 guiding principles of research methods
- respect for persons
- beneficence
- justice
Belmont - respect for persons
research is voluntary and subjects can be anonymous
beneficence - Belmont report
the potential benefits outweigh the risks
justice - Belmont report
risks and benefits are equally distributed
who determines if a study is ethical?
IRB
also called ethics committee
what does IRB stand for?
institutional review board
what is IRB’s goal?
to protect the subject
what are levels of IRB review?
- exempt
- expedited
- full board
key concepts of exempt level
use of existing data
no personal identifiers
virtually no risk
key concepts of expedited level
very low risk
no invasive interventions
no personal identifiers
key concepts of full board level
used for all interventional studies
higher than minimal risk
entire board reviews methods
who enforces the rulings of the IRB?
OHRP
what does OHRP stand for?
office of human research protections
who monitors that study during it’s conductance?
DSMB
what does DSMB stand for?
data safety and monitoring board
role of DSMB
not involved in study conduct
just review data as it comes it to make sure it complies with ethical principles
harm of the study can be positive or negative
what are the two types of harm that DSMB can use to shut down a study?
positive —- the benefits are so good that it is unethical to not allow the placebo group to have access to it
negative —- the consequences are so great that it is unethical to continue putting the subjects at risk
