Question

__________ A team of researchers were evaluating the effectiveness of motivational interviewing as a strategy to promote physical activity among patients who participated in cardiac rehabilitation. Total of 110 participants were recruited from cardiac rehabilitation center and all received motivational interviewing intervention. The data on physical activity was collected at baseline, 6 weeks and 12 months follow up.
Research question: Is there a significant difference in physical activity at 3 time points? Please indicate which statistical test should be used.

a.   Independent t-test
b.   Dependent t-test
c.   One-way ANOVA
d.   Two-way ANOVA
e.   RM-ANOVA
f.   Pearson’s Correlation
g.   Multiple Linear Regression

Answer 1

Here, we want to test whether there a significant difference in physical activity at 3 time points Therefore, there are more than two measures taken of the same group. We know that, we use repeated measures ANOVA when we want to test difference in means of more than two measures and the measures are taken from the same group.

On the other hand, Pearson's correlation and Multiple linear regression are used to test linear relationship between two or more variables.A t-test is used to test difference in mean between two groups and one way Anova is used when we want to test difference in means of more than two independent groups. Therefore, the correct answer is repeated measures ANOVA.

e.   RM-ANOVA