Critical Thinking Flashcards
What is a RCT?
“Randomized controlled trial”
- Participants randomly assigned into control or study group
- Control receives typically used treatment
- Investigational receives intervention being studied
- Considered the most rigorous study design
What is the most rigorous study design?
RCT
What is an observational study?
- Description of 1 or more groups from snapshot in time
- Exposure and disease status determined at a single point in time, a cross-section of the population
- Weakest epidemiologic study design
What is weakest study design?
Observational
What is the following type of bias:
Ascertainment
Ptn. w/ suspected outcome more extensively probed about symptoms / histories than others
What is the following type of bias:
Confounding
Effect of one factor influences effect of another
What is the following type of bias:
Detection
More Info is solicited from treatment than control group
What is the following type of bias:
Late-Look
Info gathered at wrong (too late) time point
What is the following type of bias:
Lead-time
All cases are not detected at same stage of disease: Early detection confused w/ longer survival
What is the following type of bias:
Procedure
Subjects not treated same in both groups: one group gets more visits, more attention, etc.
What is the following type of bias:
Proficiency
- Intervention not applied equally to subjects
- Due to skill, training or differences in resources or procedures used at different sites
What is the following type of bias:
Recall
Knowledge of presence of disorder alters subject recall
What is the following type of bias:
Sampling/Referral
Subjects not representative of population
What is the following type of bias:
Selection
Non-random assignment to study group
What is the following type of bias:
Susceptibility
Patients receive one intervention or another on basis of disease severity
What is the following type of bias:
Hawthorne Effect
Subject knows being observed changing her behavior
What is the following type of bias:
Pygmalion Effect
Researcher’s belief in efficacy of a treatment changes outcome
What is prevalence?
Proportion of persons in population who have particular disease at specified point in time (point prevalence) or over a specified period of time (period prevalence)
What is incidence?
The occurrence of new cases of disease or injury in a population over a specified period of time
What is reliability?
Reproducibility, consistency
What is accuracy?
Truth, absence of bias, validity
What is precision?
Exactness in measurement
Difference in sensitivity and specificity?
Sensitivity: Probability that test produces positive result when a patient is known to have ailment
Specificity: probability that test produces negative result when patient is ailment free
What is a true positive?
True Positive: both disease positive and test positive
