Week 8 Flashcards
What are the two subcategories of experimental studies
Unplanned
Planned
What is an unplanned experimental study
Natural experiments
What is a planned experimental study
Cluster or community trials
Randomized trials
What is the defining feature of an experimental study
The investigator Assign exposure
Who conducted the first randomized clinical trial
Jame lind
What did Eward Jenner do
He did an experimental study with cowpox
What are some examples of ethical issues with experimental studies
The monster study (speech therapy)
What are the different groups in experimental studies
There is a treatment group from the source population
There is a comparison group
Over time you compare the incidence of outcome in treatment and comparison groups
Whats the difference between research questions for experimental vs observational studies
Experimental studies- involve prevention or treatment
It is feasible and ethical ( small population level effect expected)
Observational studies- prevention treatment and causal factor
And experimental study is not ethical or logical
Moderate large population level effect expe
What is prevention trial
Prevention trial
Agent given to healthy or high-risk individual to prevent disease occurance
What is a therapeutic trial
Agent given to diseased individuals to treat or cure cancer
What are the unit of allocation
Individual trial
Community cluster tiral
What are some things you need to consider when making a population
Want people at in population of intrest
Risk for outcome
Among whom the intervention could be effective
People with highlikelihood of compliance with treatment
Exlcude people with conditions with drug
What does generalizability mean
The extent to which the results from a study can be generalized (or extended) to people who did not partcipate in the study
What are some things that make the study loose generalizabilty
Inclsuion/exclusion criteria
What are some reference population groups to whom results are applicable
All humans
All men, women
Urban children at risk for lead poisoning
What is the population hierachy
Refrence population
Experimental source population ( potiental partcipants)
Study population ( willing and eligible)
Informed Consent Allocation
Treatment group
Comparison group
What board must approve the study
IRB
What is randomization
Each study participant has the same probability of receving treatment
How can radominzation be achieved
Toss a coin
Computer generated
What are bad ways to do randomization
Subject self studies
Day of week order of visit
What should you consider if your group is small
Stratified randomization
What is a confounder in experimental studies
A factor that distorts the true association between an exposure and outcome
What is the ultimate goal
Treatment is the only difference between study groups
When does the two groups are the same
Study is large enough
Treatment assignment is not indluenced by investigator
What is blinding or masking
Method of ensuring that participants and/or study investigators have no knowledge or whether a study participant has been assigned to the treatment or comparison group
What is single blind
Study participant does not know whether they are receiving treatment or no treatment
What is double blind
Neither the study participant or study investigator administering the treatment knows who is receiving treatment or no treatment
What is triple blind
Neither the study partcipant nor the study invesitgator adiministering the treatment or the study investigator monitoring the effects knows
What are some sceneraios where blinidng isnt possible
Such a surgery psychotherpaty
Excercise regimens
diets
What are some ways to minimize information bias
Use a placebo maeks exposded and unexposed groups experinces as comparable as possible
And compliance
What is compliance
Following the study protcol exactly as reqiored throughout the course of the trial
What are the different goals of complaince
- Have groups be alike as possible on other important characteristics (randomization)
- Have groups be as different as possible on exposure( intervetnion)
No contamaniation
What is the worst for compliance
contamination ( inadvertent apllication of the experimental procedure to the control group)
What is descriptive anyalsis
Did randomization work
Is the distributions of potential confounding factors the same in the two groups
In the intention to treat analysis ( a+b) vs
a is compliers and b is non compliers in treatment group
(c+d) what do the values mean
+ maintains randomization and gives real life picture
- may be biased towards null due to non compiance
In the efficacy anyalsis a vs c ( compliers) what do the values mean
+ Evaluates effect of treatment in people actually treated
- Loss of benefits of randomization does not give real life picture
What is a crossover trial
Randomization so one group receives intervention then control and the other receives control than intervention
Each person acts as there own control
What are major strengths of RCT
- Demonstrate casual relationships with high level of confidence
- Researches can control exposure levels
What are some weaknesses of RCTs
- Limited applicability due to ethical reasons and at times due to artificial setting of experiment
- Potential for bias due to difference in compliance withdrawl and loss to follow up in experimental and control groups
- Usally costly and time consuming
- May have limited external validity( low generalizability)
- Risk of contamantion is high even in blinded studies
What is a cluster randomized trail
- Same methodology
- Lower risk of contamnination
- Some interventions only make sense at the group level
- More convenient
The unit of the randomization is the group
What is quantitative research
Uses structured hypothesis-driven approaches to gather data that can be statistically analyzed this is number focused and test existing hypotheses
What is qualitative research
Used in depth interviews focus groups discussions partcipant observations to explore attiudes and identify themes and patterns
What is the central concept of a qualitative study
Improve health promotion programs
Clinical process
Social change
Perception of health and illness
Can phenomena be directly measured
No
What is ontology
Nature of reality realism to relativism objectivity to subjectivity
What is realism in quantitative studies
One reality exists that can be understood by objective observation
What is relativism is qualatative studies
Multiple realities cannot be fully understood realities are subjective different interpretation based on evaluators’ beliefs
seek to understand subjective aspects of human existence
What is epistemology
Nature and definition of knowledge and truth ( positivism vs interpretivism vs critical theory)
What is epistemology in quantitative study
researchers are independent from their study subject and that researchers can control for possible biases in order to make objective measurments
What is epistemology in qualitative study
Researchers and study participants are interdependent and they create knowledge together as they interactively explore subjective topics
What is methodology
Approach to data collection an analysis
What is methodology in quantitative studies
Put a value on entities use of statistics to study relationships focus on reproducibility and generating evidence
What is methodology in qualitative studies
Meaning of phenomena focus on why and how
What is axiology
Nature of values
What is axiology in quantitative studies
Assumes rigorous procedures can control the impact of values and biases on study outcomes
What is axiology in qualitative studies
Assumes that a researchers value affects the study
What are some methodologies in the health sciences
Phenomenology, grounded theory, ethongraphy, case studies
What is phenomenology
Exploring how individuals interpret and find meaning in their own unique life experinces
What is the method for phenomenology
In depth interviews, examining transcripts to identify meanings and themes,
What is bracketing
Researchers may put aside preconceived ideas about reality to be open to new meanings that might be expressed by participants
What is grounded theory
An inductive reasoning process
Use of observations to develop general theories that explain phenomena
Simultaneous data collection and data anyalsis
No predetermined sampling strategy
Data collection continues until data saturation ( theoretical sampling)
What is Ethnography
Systematic study of people and cultures in their natural environment
Anthropological approach to develop an insiders view of the way members of sociocultural group understand their world
What type of observation to ethnographers use
Participant observations to understand a groups collective experinces
What is a case study
Use of multiple data sources to examine and understand one person group or event in detail
Observations
Interviews
Historic records
What is a mixed method study
Elements of both quantitative and qualitative methods in one single study
compare the results and internpt them
Sequential collection of data
What is the main issues with collecting qualitative data
Come engagement of researchers with participants
Hard to remain objective
High chance of bias
What is an in-deth interview
1 or 2 hours
Semi structured- list of open-ended questions as starting points
What is some techniques used for in depth interviews
Proping- prompting interviewees to providng more complete or specific response
Observation and recording- body language nonverbal communication
What is a focus group
Small number of people 8=10
1-2 hours of moderate discussion
The facilitator poses questions to the group and keep the conversation focused
What is naturalistic observation
The researcher discreetly observes study subjects in a natural setting typically without the knowledge of the subjects
What is a controlled observations
Study participants are observed in a laboratory setting and know that they are being observed
What is a Participant observation
A trained investigator seeks to understand a community by engaging with its members and immersing in its practices
What is field notes
Observation records, interview transcripts and other documents compiled during the qualitative research process
Are qualitative studies deductive and inductive
They inductive making inferences ( identifying patterns, developing theories) based on observations
Felxible can be a cycle
Are quantitative studies deductive or inductive
Making logical inferences based on facts or widely accepted premises
Linear data collection– analysis– interpretation– reporting
Deductibe
What is the analytic framework content anyalsys
Categoorizing textual data
1. Systematic coding the text using lables and categories derived from the text or from existing theories or previous research findings
2. Determining which codes occur most often and then identification of the most prominent patterns and themes in the text
What is the analytic framework of constant comparasion
A process of collecting data transcribing interviews assigning initial codes identifying themes
Include several cycles of data collection analysis and additional data collection and analysis
( Qualitative)
What is narrative anaylsis
Seeks to understand person stories themes of the stories can be interperted by other philoshpies like feminism
What is discourse analysis
Uses the tools of linguistics to evaluate the ordinary use of written andspoken language ( not a natural language)
What is the process coding
Is the use of words or short phrases to briefly summarize the contents attiudeds and processes
A lable attached to a word or a phrase
What is the goal of coding
Descriptions of participant characteristics emotions values evaaluations
What is categorizing
Grouping related codes into categories
What is a theme
Is is a concept that encompasses one or serveral categories
What is the theories
A theory is a construct that provided a systematic explanation about a phenomenon ( you can use a fourth level of coding generates a new theory about the phenomenon)
What is the order of the process
Assinging inital codes
Identify categories
Identify themes
Identify theories
( flexible and not literary)
