Lecture 14 - General Methodological Concepts of Research Flashcards
What are the two types of research or study design?
- quantitative: numbers used to represent data
- qualitative: words used to represent data
What are the two types of quantitative study designs?
- interventional: participants are forcibly allocated into study groups
- observational: participants are not forcibly allocated into study groups
What is a population?
-all the individuals making up a common group
What is a sample?
-subset of the population that is studied, ideally representative of the population
What is a null hypothesis?
- a conservative hypothesis that states that there will be no difference between groups
- goal is typically to reject the hypothesis as it is the opposite of desired outcome
What are the three stances a null hypothesis can take?
- superiority: “I’m not better”
- noninferiority: “I’m worse than”
- equivalency “I’m not equivalent”
What is probability sampling?
-when every part of the population has a known probability of being in the sample
What is simple random sampling?
Numbers are randomly assigned and subjects are either picked by random selection of numbers or by starting somewhere on the list and sequentially picking subjects
What is systematic random sampling?
-numbers are randomly assigned then from a random point subjects are selected every Nth number from that point
What is stratified simple random sampling?
-stratification of possible sample by desired characteristic followed by use of simple random sampling within strata
What is stratified disproportionate random sampling?
-disproportionate use of stratified simple random sampling when strata are not at desired proportion with the population
What is multi-stage random sampling?
-simple random sampling at multiple stages (ie. county, zip code, clinic, individual)
What is cluster multi-stage random sampling?
-multi-stage random sampling where all elements at a stage are selected
What is non-probability sampling?
- quasi-systematic sampling that is not truly random
- ie. selection of last names beginning with M-Z, individuals referenced by selected-peers
What is the difference between patient-oriented outcome and disease-oriented outcomes?
Disease-oriented:
- gives insight into disease process that a patient will likely be unable to appreciate in a clinical setting
- ie. vitamin E is a good antioxidant
Patient-oriented:
- gives outcomes that are meaningful to patients and that they can understand
- ie. vitamin E does not prevent cancer or cardiovascular disease
What is the difference between individual outcomes and combined outcomes?
Individual outcome:
- probability of a single outcome occurring
- ie. death
Combined outcome:
- probability at least one outcome from with in a possible group of outcomes
- ie. death, MI, target-vessel revascularization, or major bleeding
What are the 4 key principles of bioethics?
Autonomy:
- must decide to participate without outside influence
- must have complete understanding of risks and benefits
Beneficence
-must do good for the patient, not just society
Justice
-equal and fair treatment for all
Nonmaleficence
-do no harm
What is the difference between consent and assent?
Consent: agreement to participate of those legally and mentally capable
Assent: agreement to participate by those mentally capable but not legally capable (typically due to age)
What is an institutional review board (IRB)?
- “ethics committee”
- reviews all human studies prior to the studies beginning
- goal is to protect the rights of the study subjects
What is a data safety and monitoring board?
-monitors and reviews the study as it progresses looking for undue risk/benefit between groups
