Numbers

Question 1

Define incidence

Answer 1

Number of new cases of a disease within a population

Question 2

Define prevalence

Answer 2

Number of cases of a disease within a population at a single time

Question 3

How do you calculate relative risk?

Answer 3

    original

Question 4

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

Answer 4

1/ARR

Question 5

What is the hierarchy of scientific evidence?

Answer 5

Systematic review
RCT
Cohort
Case controlled
Cross sectional
Case report
Mechanistic 
Editorial

Question 6

What is a systematic review/meta analysis?

Answer 6

Where someone has analysed many studies in a single paper (meta analysis is a systematic review with statistical analysis)

Question 7

What is an RCT?

Answer 7

Patients are randomised into either a treatment arm or a control arm and followed up over a period of time

Question 8

What is a cohort study?

Answer 8

Patients are split into a treatment and control group and their outcomes can be paired but the grouping isn’t random

Question 9

What is a case control study?

Answer 9

Where you have a set of patients with a disease and then look into their past for risk factors

Question 10

What is a cross sectional study?

Answer 10

Where you take a snapshot of the population at a single point in time

Question 11

What is positive predictive value?

Answer 11

The proportion of patients who test positive that actually have the disease
(true positive/tested positive)

Question 12

What is negative predictive value?

Answer 12

The proportion of patients that test negative that don’t have the disease
(true negative/ tested negative)

Question 13

What is sensitivity?

Answer 13

The proportion of patients who have the disease who test positive
(truly tested positive/true positive)

Question 14

What is specificity?

Answer 14

The proportion of patients who don’t have the disease who test negative
(truly tested negative/true negative)

Question 15

Define study population

Answer 15

All individuals we are interested in eg. all children with asthma in the UK

Question 16

Define study sample

Answer 16

Group of individuals drawn from a population of interest that is studied to learn about the population

Question 17

What is a 95% CI?

Answer 17

A range of values that you can be 95% certain contains the true mean of the population

Question 18

Define p value

Answer 18

The probability you would get your result if the null hypothesis is true

Question 19

What is standard deviation?

Answer 19

Describes variability within a particular sample

Question 20

What is standard error?

Answer 20

A measure of variability of summary statistics between sample means

Question 21

When is a CI statistically significant?

Answer 21

Difference between two means - exclude 0 is statistically significant
Ratio - exclude 1 is statistically significant

Question 22

When is cost-utility analysis used?

Answer 22

Uses QALYs and incremental cost gained per QALY gained

Question 23

When is cost-effective analysis used?

Answer 23

Outcomes are measured in natural units eg. pain score with incremental cost per life year gained

Question 24

When is cost-benefit analysis used?

Answer 24

Outcomes are measured in monetary units to ascertain the net monetary benefit

Question 25

When is cost-minimisation analysis used?

Answer 25

Measured in cost when outcomes have exactly the same outcome

Question 26

What is the incremental cost effectiveness ratio?

Answer 26

Measure of monetary value against QALYs

= diff. in cost./diff. in benefits