Week 2 Flashcards
What is a three step explanation of the research process?
- Pose a question
- Answer the question
- Present the answers
“Pose a Question”
- understand the research field
- indentify research question
- FINER framework
“Answer the Question”
- formulate hypothesis
- plan study
- collect data
- analyze data
“Present the Answers”
- interpet and discuss the results
- derive conclusions
FINER Framework
used for posing a research question
* Feasible
* Interesting
* Novel
* Ethical
* Relevant
FINER Framework
Feasible
- adequate numbers of subjects
- adequate technical expertise
- affordable in time and money
- manageable in scope
FINER Framework
Interesting
should cause intrigue in investigators, peers, and community
FINER Framework
Novel
confirms, refutes, or extends previous findings
FINER Framework
Ethical
respects rights, dignitiy, and well-being of participants
FINER Framework
Relevant
- to scientific knowledge
- to clinical and health policy
- to future research
Independent Variable
variables that are manipulated or measured by the researcher
Dependent Variable
variables being measured in order to determine the effects of independent variable
Study Subjects
in what animals model or population you will study the question
Graduate School
NIH NRSA F31 (National Research Service Award)
supports predoctoral students in biomedical research
Graduate School
NSF Fellowship Program
offers funding to graduate students in science, technology, engineering, and mathematics
Postdoc
NIH NRSA F32
a grant that provides funding to support promising postdoctoral researchers in biomedical and behavioral sciences
Postdoc
NIH NRSA T32
a grant awarded to institutions to fund research training programs for postdoctoral students in various biomedical, behavioral, and clinical research fields
Postdoc
NIH K Awards
Provides career development support for early-career researchers transitioning to independent research
Postdoc
NIH K99/R00
- Pathway to Independence Award
- designed to help postdoctoral researchers transition to independent research positions; It is a two-phase grant
Faculty
NIH R01
research project grant
Postdoc
NIH R03
small research grant
Postdoc
NIH R21
exploratory/developmental research grant
What are NIH review criteria?
- significance
- innovation
- investigator (s)
- approach
- environment
Define Cause-Effect Relationship
a relationship in which one event (cause) makes another event happen (effect)
Define Cause
an event, condition, or characteristic that precedes a health outcome
What are the main categories of establishing a cause-effect relationship?
- Correlation
- Temporality
- Alternative Explanation
Cause-Effect Criteria
Correlation
is there a relationship between the independent variable and the dependent variable?
Cause-Effect Criteria
Temporality
does the cause precede the effect?
Cause-Effect Criteria
Alternative Explanation/Mechanism
can the observed associations be explained by alternative (non-causal) mechanisms, or extraneous variables?
Which of Hill’s criteria fall under “Correlation”?
- strength
- consistency
- specificity
- biological gradient
Hill’s Criteria
strength
magnitude of the effect and statistical significance
Hill’s Criteria
consistency
similar results repeatedly observed by different persons, places, circumstances and times
* integrating results from multiple types of studies
Hill’s Criteria
specificity
specific conditions (exposures) linked to particular sites and specific outcomes
Hill’s Criteria
biological gradient
linear relationship between the dose of exposure and risk of diease or severity of outcome
Which of Hill’s criteria fall under “Alternative Explanation”?
- plausability
- coherence
- experiment
- analogy
Hill’s Criteria
plausability
is there a plausible biological mechanism?
Hill’s Criteria
coherence
does it contradict known biological mechanisms or other specific facts?
Hill’s Criteria
experiment
well designed experiments should be powerful tools to investigate causality
Hill’s Criteria
analogy
when similar exposure-outcome relationships have already been established, it will be easier to make causal inference
Validity
refers to the credibility or believability of the research
Reliability
refers to the consistency or repeatability of the results over time or across different observers
Internal Validity
the degree to which a study accurately establishes a cause-and-effect relationship between variables, free from confounding factors
External Validity
generalizability; the extent to which the results of a study canbe generalized to other populations, settings, or times beyond the specific conditions of the experiment
Errors
defined as the difference between the true value of a measurement and the recorded value of a measurement
Errors
Random Error
- “noise in the system”
- no preferred direction (averages zero)
- tends to decrease with larger sample sizes or repeated measurements
Errors
Non-random / Bias
- not due to chance alone
- has direction and magnitude (averaging does not equal zero)
- threat to internal validity
Accuracy
How close a measured value is to the true or accepted value
Precision
the consistency or repeatability or measurements, regardless of how close they are to true value
Confounding
influence of third variables (extraneous variable) in a study which leads to an incorrect estimate of the association between independent and dependent variables
What are characteristics of a confounder?
- associated with the exposure
- associated with the outcome
- not on the causal pathway
Confounding
Positive Confounding
makes the association appear stronger that it is
Confounding
Negative Confounding
makes association appear weaker than it is
Confounding
Qualtitative Confounding
changes the direction of association between exposure and outcome
* positive to negative
* protective to harmful
Mediator
when a variable lies in the causal pathway that link the exposure to the outcome
How can confounding be managed?
Design:
* randomization
* restriction
* matching
Analysis:
* adjustment
* stratification
Effect Modification
situation where a third variable modifies the effect of exposure on disease outcome
How is Effect Modification similar to Confounding?
effect modification is about a third variable involved in the relationship between exposure and outcome
How is Effect Modification unlike Confounding?
effect modification is usually not considered bias b/c it often reveals underlying biological mechanisms that impact the effects of the exposure
