Biostats Flashcards
Relative risk formula
risk in tx group / risk in control group
In this type of distribution, the mean, median, and mode are the same value.
normal
retrospective comparisons of cases (patients with a disease) and controls (patients without the disease)
case control study
retrospective or prospective comparisons of patients with an exposure to those without an exposure
cohort study
Which of the following statements are true regarding the p-value?
a. If the alpha in a study is 0.01, p < 0.05 indicates the result is statistically significant.
b. It represents the level of clinical significance.
c. A study result is considered statistically significant if the p-value is less than alpha.
d. It provides info for rejecting or not rejecting the null hypothesis.
e. It can be set to any number by the investigator and be clinically relevant.
c, d
NNT formula
1 / (risk in control group - risk in tx group)
(% risk in control group) - (% risk in tx group)
absolute risk reduction
describes how effectively a test identifies patients with the condition
sensitivity
describes how effectively a test identifies patients without the condition
specificity
This type of analysis can be used to compare programs with similar or unrelated outcomes, as long as the outcome measures can be converted to dollars.
cost-benefit
Rank the studies from most reliable to least reliable:
Case control studies
Randomized controlled trials
Meta-analyses
Cohort studies
Case series
Meta-analyses, randomized controlled trials, cohort studies, case control studies, case series
This type of study combines data from different, but related studies, in order to increase the power of the study.
meta-analysis
What kind of error occurs when the alternative hypothesis is accepted and the null hypothesis is rejected in error?
type 1
What kind of error occurs when the null hypothesis is accepted when it should have been rejected?
type 2
represents the spread (or variability) of data from the mean when data is normally distributed
standard deviation