Flashcards in biostatistique Deck (145)
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1
standard deviation normal distribution a 68%
SD a 1 from the mean
2
standard deviation normal distribution a 95%
SD a 2 from mean
3
standard deviation normal distribution a 99,7%
SD a 3 from the mean
4
example mean a 230 mg/dl pour le cholesterol and SD a 10,what's the value for cholesterol if observations are 95%
210-250
5
disease with increasing prevalence and stable incidence what happened(2)
any rx which prolongs life
good quality of care
6
Quid of PPV(2)
positive predictive value
pobability of having the disease if the result test is positive
7
quid of negative predictive value
probability of having the disease if the test is negative
8
quid of null hypothesis
no relationship between exposure and outcome
9
example of null hypothesis
CRP high and colon cancer ,no relationship
10
what to consider when evaluating the effectiveness of new trial drug
the natural history of the disease
11
example drug effectiveness and drug trial(2)
effectiveness of antiviral drug and flu
no exact conclusion can be drawn becausecommon cold is a self limited disease
12
in hazard ration interpretation what are the 2 key factors to consider(2)
control arm
rx arm
13
quid of hazard ratio <1
the event will occur in the control arm
14
quid of hazard ratio > 1
the event will occur in the rx arm
15
practice of hazard ratio
the chance for an event to occur during taking a drug for instance
16
interpretation of hazard ration close to one
no difference for an event to occur in the 2 groups rx arm and control arm
17
what information is critical to successfull randomization
baseline characteristics
18
what an ideal randomisation
process to minimize selection biais and achieves possibility of cofounding variables
19
a study is done using placebo and Rx,the assignment of the rx in teh two arm is done randomly using numbers generated by computer what randomization helps to do in ths case?
to eliminate confounder
20
what methods are used to eliminate cofounder during analytic stage of study
stratified analysis
modeling
21
what methods are used to eliminate cofounder during adesign stage of study(3)
matching
restriction
randomization
22
clue for randomization(2)
Rx group
Placebo group
23
when using randomization
during clinical trials
24
quid of restriction
when you limit your study to one group for example one sexe is considered
25
problem with restriction
you cannot generalize your finding in the population
26
when using matching
control studies
27
importance in using macthing(2)
when you want to study risk factor(
exposure and outcome
28
practice of macthing
you will take a group with a known risk factor and another one without it and compare
29
quid of false negative
the test is negative but you have the disease
30
