forest plots, funnel plots and heterogeneity

Question 1

forest plots use

Answer 1

odd ratios

Question 2

size of the square

Answer 2

represents the weight given to each study- the larger the square the bigger the weight

Question 3

pooled effect size is denoted by

Answer 3

a diamond

Question 4

vertical line- 1

Answer 4

no effect

Question 5

if the CI line cross 1

Answer 5

the study didn’t show significance

Question 6

p value

Answer 6

the probability that if this was repeated you would ge the same result

Question 7

funnel plots represent

Answer 7

publication bias

Question 8

larger studies have

Answer 8

higher/ lower odds ratios - smaller standard error

Question 9

negative studies are

Answer 9

much less likely to be published

Question 10

due to negative studies being less likely to be published

Answer 10

systematic reviews ill have more positive than negative outcome trials

Question 11

forest plots show that

Answer 11

studies with equal standard error are subjected to publication bias based on whether they yield positive or negative results

Question 12

meta-analyses are subsets of

Answer 12

systematic reviews

Question 13

systematic reviews are

Answer 13

subsets of all reviews- narrative reviews

Question 14

heterogeneity is

Answer 14

the difference in studies not due to chance

Question 15

hereogenity reduces their ability to be used in

Answer 15

meta-analyses

Question 16

clinical heterogeneity

Answer 16

differences in:

• patients/study setting
• study design / quality
• interventions
• outcomes (how they are measured)

Question 17

statistical heterogeneity

Answer 17

individual trials have results not consistent with each other

• benefits vs harms
• size of benefit and harm
• evaluated statistically

Question 18

I2

Answer 18

the percentage of variation across studies that is due to heterogeneity and not due to chance

Question 19

0.25

Answer 19

low heterogeneity

Question 20

0.5

Answer 20

moderate

Question 21

0.75

Answer 21

high

Question 22

when looking at forest plots, evidence of heterogeneity

Answer 22

• if the plots are on different sides of 1

- wide CIs

Question 23

95% CI’s

Answer 23

we can be 95% certain that the true value lies within this range of values