Module 3 Key: Flashcards
Describe Type I and II errors
Type I : false positive
Wrongly concluding that there is an effect of the intervention when in reality there is none
Type II : false negative
Wrongly concluding that there is no effect of the intervention when in reality there is one
How do you understand this:
Randomization therefore controls biases associated with known and unknown factors
For example, you have completed an RCT whose results have been published. A few years later, we discovered a new prognostic factor strongly associated with the CRP used in your RCT; factor that was not assessed in your RCT. Is there a risk of confounding bias caused by this factor in your RCT? If your RCT was very well balanced on all the variables measured at recruitment, it is very likely that this new factor (if it had been measured) would have been balanced as well. The risk of bias is therefore very low.
True or False:
In a prospective study, the exposure precedes the disease.
True
Temporal relationship
This means that exposure precedes disease.
Multiple Choice: What does a strong association between exposure and disease imply?
A. Biases and precision have potentially less impact.
B. The disease is caused by the exposure.
C. The exposure is caused by the disease.
D. The disease and exposure are not related.
A. Biases and precision have potentially less impact.
Magnitude of response/Strength of association
If the magnitude of the association between exposure and disease is large enough, bias and precision potentially have less impact.
Multiple Choice: What does the specificity of the association refer to?
A. The disease can be predicted by a primary factor.
B. The disease can have multiple causes.
C. The treatment can have multiple effects.
D. All of the above.
D. All of the above.
Specificity of the association
True or False: In a randomized controlled trial (RCT), the risk of disease decreases as the exposure increases
True
The more intense the exposure, the more the risk increases (e.g. tobacco and lung cancer)
Multiple Choice: What does the dose-response effect refer to?
A. The more intense the exposure, the higher the risk.
B. The less intense the exposure, the higher the risk.
C. The intensity of exposure does not affect the risk.
D. The risk is always high, regardless of the intensity of exposure.
The more intense the exposure, the higher the risk.
True or False: Stability of the association states that the same associations should not be excpected with other populations/cohort/studies.
FASLE
The same associations are observed with other populations/cohorts/studies.
Multiple Choice: What does biological plausibility refer to?
A. There is a known biological mechanism that can explain the causal link.
B. There is no known biological mechanism that can explain the causal link.
C. The biological mechanism is irrelevant to the causal link.
D. The causal link is irrelevant to the biological mechanism.
A. There is a known biological mechanism that can explain the causal link.
What factor of BH does this describe.
Previous studies support the fundings of a present work.
Cohérence
What is Évidence concomitante?
évidence sur la reproductibilité et la similarité des résultats avec d’autres études dans d’autres populations
What is Évidence mécanistique?
évidence sur le processus qui lie l’intervention/l’exposition à la maladie
basically studying the biological mechanism that explains the cause
True or False
Sample size does not reduce the risk of bias.
True
Precision increases with sample size but sample size has no impact on bias.
True or false:
L’erreur aléatoire d’une moyenne obtenue d’une échantillon de patients est quantifiable. Cet énoncé est :
True
À quoi servent les critères de Bradford Hill ?
Déterminer les conditions sous lesquelles une exposition (Y) cause une maladie (X) lorsqu’une association est observée entre cette exposition Y et cette maladie X.
