EBM menti quiz

Question 1

best study to determine prevalence of a disease

Answer 1

cross-sectional study
–> prevalence

cohort study - follow up over time, incidence of new cases

Question 2

in a RCT, what is reduced by randomisation?

Answer 2

selection bias

Question 3

a study that aims to establish normal height of 4y/o children by measuring heights on school entry

Answer 3

cross sectional

Question 4

a study that compares 2 groups of 4y/o with similar characteristics - one group is given a drug + the other a placebo - growth of each is measured after this intervention

Answer 4

controlled trial

Question 5

external validity

Answer 5

the extent to which one can appropriately apply the results to other populations

Question 6

best study design to research the aetiology of a disease

Answer 6

cohort
-> importance of time frame

Question 7

statistical significance

Answer 7

results of a study are unlikely to have arisen from chance alone

Question 8

what does qualitative research seek to analyse?

Answer 8

the data which reserchers collct from people in relation to their experiences + circumstances

Question 9

what is it called when there is no longer any need to sample more people to reach new conclusion or to back up or challenge existing conclusions?

Answer 9

saturation

Question 10

exclusion criteria

Answer 10

clear preference for intervention or control
- by patient or doctor

Question 11

qualitative research methods

Answer 11

ask people
- interview
- focus group
- (some ) questionnaires

observe people
- ethnography
- non-participant observation

Question 12

triangulation

Answer 12

area under investigation looked at from different perspectives
- 2 or more research methods

ensure understanding is complete as possible or confirm interpretations

iterative approach -> alter methods as study progresses

Question 13

research governance

Answer 13

the broad range of regulations, principles + standards of good practive that ensure high quality research

Question 14

how is sensitivity calculated

Answer 14

(how well the test detects having the disease)

number of results where disease is detected in people with the disease / number of people with the disease

Question 15

how is specificity calculated?

Answer 15

(how well the test detects NOT having the disease)

number of “normal” results where disease is NOT detected in people withOUT the disease / number of people without the disease

Question 16

a highly specific test would

Answer 16

correctly detect NO disease
very few false positives

Question 17

positive predictive value

Answer 17

how reliable is the test result when it shows disease is present

Question 18

calculating positive predictive value

Answer 18

number of people with a positive test result + have the disease / number of people with a positive test result (showing disease)

Question 19

negative predictive value

Answer 19

how reliable is the test result when it shows disease is NOT present

Question 20

calculating negative predictive value

Answer 20

number of people who have a negative test result + do NOT have the disease / number of people with a negative test result

Question 21

what is positive + negative predictive value affected by?

Answer 21

prevalence