Definitions

Question 1

Prevelance

Answer 1

Proportion of people have a disease at a particular time. This is old and new cases

Question 2

Period prevelance

Answer 2

Proportion of people who have a disease over a particular time period

Question 3

Point prevelance

Answer 3

Proportion of people who have a disease at a particular time

Question 4

Lifetime prevelance

Answer 4

All the people who have had or have a disease

Question 5

Incidence

Answer 5

The number of new cases of a disease

Question 6

Null Hypothesis

Answer 6

There is no link between two things

Question 7

Hypothesis

Answer 7

There is a link between two things

Question 8

Sensitivity

Answer 8

How good a test is at predicting that someone does have a disease

Question 9

Specificity

Answer 9

How good a test is at predicting that someone does not have a disease

Question 10

True positive

Answer 10

The number of people who are diagnosed a having a disease that actually have it

Question 11

True negative

Answer 11

The number of people who are diagnosed as not having a disease that actually dont have it

Question 12

Alpha, Type 1 Error

Answer 12

Incorrectly rejecting the null when it is right

FALSE POSITIVE

Question 13

Beta, type 2 error

Answer 13

Wrongly rejection the hypothesis when it is right

FALSE NEGATIVE

Question 14

Postive predictive value

Answer 14

The proportion of positive results that actually have it

Question 15

Negative predictive value

Answer 15

The proportion of negative results that actually have it

Question 16

Receiver operating characteristics curve

Answer 16

Plotted to work out where the cut off point should be for FP and FN

Question 17

Efficiency

Answer 17

How good a test is. All the write answers divided by all the answers

Question 18

Stratification

Answer 18

Grouping common factors to try and reduce confounding variables

Question 19

Confounding variables

Answer 19

An extraneous variable in a statistical model that correlates(directly or inversely) with both the dependent variable and the independent variable.

Question 20

Standardized Mortality Ratio (SMR)

Answer 20

quantity, expressed as either a ratio or percentage as quantifying the increase or decrease in mortality of a study cohort with respect to the general population.

This is an indirect standardisation

Question 21

Direct standardisation

Answer 21

Direct standardisation requires that we know the age-specific rates of mortality (or morbidity) in all the populations under study

Question 22

Indirect Standardisation

Answer 22

Indirect standardisation only requires that we know the total number of deaths (or cases) and the age structure of the study population, and thus indirect standardisation may be the only feasible method if age-specific rates are not available.

Question 23

What is a de facto census?

Answer 23

A census worked out based on where people are on the census night

Question 24

What is a de jure census?

Answer 24

A census based on where people usually live