MRCPsych Paper B - Critical review

Question 1

Type of randomization - using odd/even numbers of DOB

Answer 1

Quasi-randomization
*because it is not reproducible

Question 2

Type of randomization - coin toss

Answer 2

not randomization

Question 3

Type of randomization - computer generated random list

Answer 3

Simple randomization

Question 4

Type of randomization - blocks of 6

Answer 4

Block randomization

Question 5

Type of randomization - randomize clusters or catchment zones, not individuals

Answer 5

Cluster randomization

Question 6

Type of randomization - next allocation is based on the characteristics of what is already present

Answer 6

Minimisation

Question 7

How to control confounders?

Answer 7

Restriction
Matching
Randomisation
Stratification
Multivariate analysis

Question 8

Type of bias - difference between hospital/admitted population and community population

Answer 8

Berkson bias

Question 9

Type of bias - using incidence rather than prevalence in determining causation computations

Answer 9

Neyman bias

Question 10

Type of bias - exclusion of comorbidities in a non-representative sample

Answer 10

Diagnostic purity bias

Question 11

How to control measurement bias?

Answer 11

Blinding

Question 12

How to control analysis bias?

Answer 12

Intention to treat analysis

Question 13

Statistical study to quantify heterogeneity

Answer 13

Chi-square - Cochran’s Q(uantify)
*Q(uantify)

Question 14

Statistical study to differentiate between heterogeneity and chance

Answer 14

I2 statistic

Question 15

Economic study - used to decide how to spend the allocated money effectively

Answer 15

Cost benefit

Question 16

Economic study - used to compare just the costs

Answer 16

Cost minimisation

Question 17

Economic study - used when both interventions result in an outcome that can be measure using the same clinical scale

Answer 17

Cost effectiveness

Question 18

Economic study - used when considering the holistic effect of what is being measured (DALY, QOL, life utility units)

Answer 18

Cost utility

Question 19

Economic study - used when different interventions AND different outcomes are being measured using natural units

Answer 19

Cost consequences

Question 20

Sensitivity analysis - effect of resampling the data set

Answer 20

Bootstrapping

Question 21

Sensitivity analysis - the uncertainty in each unit is assumed to possess a probability distribution while estimating the predicted effects

Answer 21

Monte-Carlo simulation

Question 22

What is PDSA?

Answer 22

Plan Do Study Act

Question 23

What is FOCUS?

Answer 23

Finding - process to improve
Organizing - a team
Clarifying - current knowledge
Understanding - causes of variation
Selecting - improvement process

Question 24

What is FADE?

Answer 24

Focus - define the problem
Analyze - data collection for current knowledge and root cause of the problem
Develop - action plan
Execute - implement
Evaluate - measuring and monitoring system

Question 25

Arrangement of central tendency in a negative/left skew?

Answer 25

Mean Median Mode *alphabetical

Question 26

Arrangement of central tendency in a positive/right skew?

Answer 26

Mode Median Mean

Question 27

Std. error of mean (SE) is always __ to Std. deviation

Answer 27

smaller *SE < SD

Question 28

The rectangle of a box and whisker plot pertains to what?

Answer 28

50th to 75th percentile

Question 29

The line cutting through the rectangle of a box and whisker plot pertains to what?

Answer 29

median value

Question 30

Percentage of data that lie within 1 SD

Answer 30

68% *Shaq Nash vs 2 = 34 + 13 + 2

Question 31

Percentage of data that lie within 2 SD

Answer 31

95% *Shaq Nash vs 2 = 34 + 13 + 2

Question 32

Percentage of data that lie within 3 SD

Answer 32

99% *Shaq Nash vs 2 = 34 + 13 + 2

Question 33

What is a Type 1 error

Answer 33

False positive, α

Question 34

What is a Type 2 error

Answer 34

False negative, β

Question 35

How to increase the power of a study?

Answer 35

increase significance level increase sample size increase effect size decrease variability use a one sided test

Question 36

Value of no difference of OR

Answer 36

1

Question 37

Value of no difference of RR

Answer 37

1

Question 38

Value of no difference of ARR

Answer 38

0

Question 39

Value of no difference of RRR

Answer 39

0

Question 40

Value of no difference of NNT

Answer 40

∞

Question 41

How can you decrease the width of the CI?

Answer 41

Use a smaller degree of CI (95% to 90%) Reduce SD by stratifying Increase sample size = N

Question 42

Effect size scores and interpretation

Answer 42

0.5 ± 0.3 = medium (vs small, large) *effect size score is that amount of SD above the average person in the control group

Question 43

How to correct for multiple testings?

Answer 43

1. Bonferroni correction - adjust the p-value/ significance levels 2. Family-wise error - probability one of the data sets is a Type 1/ False Positive error 3. False discovery rate - control the PROPORTION of Type 1/ False positive error

Question 44

Average duration of test-retest correlation used in psychiatry

Answer 44

2-14 days

Question 45

Arbitrary cutoff for Cronbach's alpha

Answer 45

0.70

Question 46

Type of validity - agreement between instruments that measure the same construct

Answer 46

Convergent validity

Question 47

Type of validity - disagreement between two scales measuring different constructs

Answer 47

Divergent validity

Question 48

Type of validity - sensitivity to change

Answer 48

Experimental validity