Biostats

Question 1

…. study has subjects that are divided into groups based on the presence or absence of a presumed risk factor and are followed prospectively.

Answer 1

Cohort studies

Question 2

Type 1 error is exposed by investigating the … of the results

Answer 2

p-value (statistical significance)

Question 3

Type 2 error is exposed by investigating the …. of the study

Answer 3

power

Question 4

How do you calculate sensitivity?

Answer 4

true positives (a) / true positives (a) + false negatives (c)

Question 5

How do you calculate specificity?

Answer 5

true negative (d)/ true negative (d) + false positive (b)

Question 6

How do you calculate positive predictive value (PPV)?

Answer 6

true positives (a)/ true positives (a) + false positives (b)

Question 7

How do you calculate negative predictive value (NPV)?

Answer 7

true negative (d)/ true negative (d) + false negative (c)

Question 8

How do you calculate NNT (number needed to treat)?

Answer 8

NNT = 1/ ARR

ARR (absolute risk reduction) = percent placebo- percent treatment

Question 9

… is proactively identifying potential sources of failure in a process before they fail, identifying the cause and consequences of these potential failures, and planning action items to prevent them

Answer 9

Failure modes and effects analysis