Topic 8: measure of association of mean difference

Question 1

Describe mean difference

Answer 1

• Comparison between 2 means
• Assesses presence of association between categorical exposure + numeric outcome

Question 2

When does mean difference apply

Answer 2

1) Comparing between categories of a variable = between subjects e.g. men/women
2) Comparing in a group at different time points = within subjects + repeated measure design e.g. blood glucose at different times

Question 3

How to calculate mean difference

Answer 3

Mean in group 2/time point 2 - Mean in group 1/time point 1

Question 4

What stat tests give a mean difference between 2 groups?

Answer 4

1) Independent sample t-test = 2 categories
2) One-way analysis of variance = >2 categories

Question 5

What stat tests give mean differences between paired groups?

Answer 5

1) Paired sample t-test = 2
2) Repeated measures analysis of variance = >2

Question 6

What stat test is used to give mean difference between groups with repeated measures?

Answer 6

Mixed-design analysis of variance