Lecture 4 Sp25 Flashcards
(42 cards)
What are preclinical trials?
Testing of a drug, procedure or other medical treatment in animals before trials in humans
Involves evaluating the drug’s toxic and pharmacological effects through in vitro and in vivo laboratory animal testing.
What is non-differential misclassification?
Classification errors of same magnitude in both groups, biased toward null
Dampens association; reduces power of study to detect a significant difference between groups.
What is differential misclassification?
Classification errors differ between groups, accuracy of disease or exposure classification differs
Risk estimates can be biased in either direction, inflating or dampening association.
Define misclassification.
Incorrect determination of disease or exposure status
Can be differential or non-differential; often influenced by information bias.
What is random error?
Variation in a measurement that has no apparent connection to any other measurement, regarded as due to chance
Generally biases toward the null.
What is the difference between intention to treat and per protocol analysis?
Intention to treat analyzes as randomized; per protocol analyzes those who completely adhere to protocol
Intention to treat assesses efficacy; per protocol assesses effectiveness.
What is equipoise in clinical trials?
Genuine doubt about efficacy of treatment yet sufficient belief that it may work
Essential for ethical conduct in clinical trials.
What is the purpose of Phase IV trials?
Gather information on the drug’s effect in various populations and side effects associated with long-term use
Conducted after the drug has been marketed.
What occurs during Phase III trials?
Given to large groups to confirm effectiveness, monitor side effects, and compare to commonly used treatments
Collects information for safe usage.
What is the main goal of Phase I trials?
Evaluate safety, determine safe dosage range, and identify side effects
Usually involves healthy volunteers.
What is the definition of bias in research?
Systematic error in the design, conduct, or analysis of a study
Causes over- or under-representation of one or more cells in the 2x2 table.
What is meant by the term ‘randomization’ in clinical trials?
The process of assigning participants to different treatment groups by chance
Helps to ensure that the groups are comparable.
What are the types of blinding in clinical trials?
Unblinded, single-blind, double-blind, triple-blind
Each type involves different levels of knowledge about treatment assignments.
What is a major challenge in conducting experimental studies?
Need for extensive training of field and intervention staff
Other challenges include ethical use of control and randomization.
What is the significance of multi-disciplinary teams in research?
Multiple perspectives are needed to perform studies effectively, especially in interventional work
Key members may include epidemiologists, clinicians, and field staff.
What is the definition of error in research?
A false or mistaken result obtained in a study or experiment
Can be random or a result of systematic bias.
True or False: Bias can be compensating.
True
Biases in comparison groups can cancel each other out.
What is the main issue with differential bias?
Leads to incorrect conclusions regarding outcomes or predictors
It creates systematic errors that can misrepresent the truth.
Fill in the blank: The _______ principle emphasizes that there must be genuine doubt about treatment effectiveness in clinical trials.
Equipoise
What is the concept of design in epidemiology?
Framework for conducting and evaluating studies
What does CEDD stand for?
Course Educational Design Document
What are the main threats to validity in research?
Confounding, misclassification, interaction
What is the significance of randomization in experimental designs?
Foundation to understand bias and ensure comparability
What is ‘intention to treat’ in the context of RCTs?
Analysis based on initial treatment assignment regardless of adherence
