Statistics Flashcards
What study calculates the incidence?
Cohort study
What study calculates the prevalence?
Cross-sectional study
False (-) ratio =
1-sensitivity
thus, sens is good at ruling OUT dz.
Higher the NPV, the higher the Sens
False (+) ratio =
1-specificity
thus, spec rules IN dz.
The higher the PPV = the higher the Spec
The higher the disease prevalence = higher PPV
The lower the disease prevalence = higher NPV
Post test odds =
Pretest odds * LR
What type of variables reduce the internal validity of a study?
Confounding variables
Type 1 error
Type 2B error
Type 1 = saying there is a difference when there is NOT difference. (incorrectly rejecting the null hypothesis)
Type 2B = saying there is no difference when there IS a difference. (incorrectly accepting the null hypothesis)
Power =
1-B
Power is the probability that a study will find a correct significant difference. Increasese with more people in the study.
If the p value is higher than 0.05….
Then the study is NOT valid. P will increase with a lower confidence interval
You do not need informed consent…
in emergency situations, when the pt is incapacitated (must get surrogate.)
Pregnant pts can reject treatment that will save their baby if there is a chance that the treatment will hurt themselves.
yep
MDs can overrule a parents wishes if…
their wishes will/may harm the kid
Order of surrogate for patients…
SPOUSE CHiPS in For the patient
- SPOUSE
- Children
- parents
- Siblings
- Friends
