Stats Etc

Question 1

What is the case K-series

Answer 1

Report on series of patients with an outcome of interest.

No control group

Question 2

Cohort study

Answer 2

Identification of two groups
One received the exposure
One did not
Follow-up cohorts for outcome

Question 3

What is the confidence interval a measure of

Answer 3

Quantifies the uncertainty in measurement.

Reported as 95% = range of values within which we can be 95% sure that the true value for the whole population lies

Question 4

What is crossover design study

Answer 4

Administration of two or more experimental therapies one after the other in a specified or random order to the same group of patients

Question 5

what is a cross-sectional study

Answer 5

Okay sedation of a defined population at a single point of time.
Exposure and Outcome determined simultaneously

Question 6

What are the control event rate (CER) and experimental event rate (EER)

Answer 6

Proportion of patients in the group in whim the event is observed
E.g. 27/100 = 0.27

Question 7

What is incidence

Answer 7

The proportion of new cases of the target disorder in the population at risk during a specified time interval

Question 8

What is intention-to-treat analysis

Answer 8

Analysis for RCT where all patients randomly assigned to one treatment or analyse together regardless of whether they completed all receive the treatment
Preserves randomisation

Question 9

What is the likelihood ratio

Answer 9

Likelihood that a given test result would be expected in a patient with the target disorder compare to the likelihood of the same result in a patient without the target disorder

Question 10

What is a meta-analysis

Answer 10

Systematic review using quantitative methods to synthesise and summarise results

Question 11

What is negative predictive value

Answer 11

Proportion of people with a negative test you are free from the target disorder

Question 12

What is number needed to treat

Answer 12

Inverse of the absolute risk reduction

Number of patients needed to treat to prevent one bad outcome

Question 13

What does odds mean

Answer 13

Ratio of people incurring outcome compare to a number of people who don’t

Question 14

What is an odds ratio

Answer 14

Ratio of the odds of people having a target to sort it in the experimental group relatives the odds of having the target disorder in the control group

Question 15

What is positive predictive value

Answer 15

Proportion of people with a positive test result who have the target disorder

Question 16

What is posttest odds

Answer 16

Odds the patient has target disorder after test completed

Pre-test odds x likelihood ratio

Question 17

What is prevalence

Answer 17

Proportion of people with The target disorder in population at risk at a specific time

Question 18

What is risk ratio

Answer 18

Ratio of the risk of the outcome event in the treated group to the risk of the event in the control group
RR = EER/CER

Question 19

What is sensitivity

Answer 19

Proportion of people with target disorder who have a positive test result

Question 20

What is specificity

Answer 20

Proportion of people without the target disorder who have a negative test result

Question 21

What is relative risk reduction

Answer 21

Proportional reduction in rates of the bad outcome between experimental and control groups
(EER-CER)/CER

Question 22

What is absolute risk reduction

Answer 22

Absolute arithmetic difference in rates of bad outcome between experimental and control groups
(EER-CER)

Question 23

Equation for number needed to treat

Answer 23

1/ARR

Question 24

What is the case control study

Answer 24

Study involves identifying patients with the outcome of interest and control patients without the same outcome.
Look back to see if they had exposure of interest