Hello,
I have read about but cannot find the answer to my queries.
I am doing a study looking at the effects of positive thinking (PT) and exercise on depression. I'll be measuring at LEAST 2 outcomes. So far, depression levels and quality of life score levels using standardise inventories, like the beck depression inventory. Possibly a few more. The hypothesis is that exercise and PT will lower levels of depression and increase quality of life but exercise will be more effective.
So, I have one IV (group type) with 3 levels (exercise, PT and a no-treatment control group) and a minimum of two DVs (depression level and quality of life levels).
So, I am thinking that I should perform a MANOVA when I have my results. However, I have a few queries.
First of all, I would obviously want to compare baseline measures to ensure between group homogeneity. What is the best way/are the best ways to do this? (Do I even need to perform an analysis?)
Secondly, I want to do both intention to treat (ITT; all participants randomised to each condition) and per protocol (PP; only participants who did a certain amount of exercise etc) analysis. They both have separate advantages and I would like to include both.
What is the best way/are the best ways to do this? Would I perform a separate MANOVA for each and then do some kind of adjustment like bonferroni? Or include them in the MANOVA as separate groups?
I think I have read somewhere that the same participants should not be used in a MANOVA unless it is a repeated measures but not sure about this.
Lastly, if I wanted to do the above study, with ITT and PP analyses AND wanted to take group measures at 5 points in time and compare these between groups, how would I best go about doing that? I'm thinking some kind of multilevel model, but none of my books cover this, and I don't know if that would be getting out of my depth. Alternatively, could I do a repeated measures MANOVA?
I am working with SPSS.
A lot here I know. As I said, I have read about a fair bit but can't seem to find instructions/recommendations of what kind of test to do in any of my books.
Any help would be very much appreciated.
Thank you muchly guys

I have read about but cannot find the answer to my queries.
I am doing a study looking at the effects of positive thinking (PT) and exercise on depression. I'll be measuring at LEAST 2 outcomes. So far, depression levels and quality of life score levels using standardise inventories, like the beck depression inventory. Possibly a few more. The hypothesis is that exercise and PT will lower levels of depression and increase quality of life but exercise will be more effective.
So, I have one IV (group type) with 3 levels (exercise, PT and a no-treatment control group) and a minimum of two DVs (depression level and quality of life levels).
So, I am thinking that I should perform a MANOVA when I have my results. However, I have a few queries.
First of all, I would obviously want to compare baseline measures to ensure between group homogeneity. What is the best way/are the best ways to do this? (Do I even need to perform an analysis?)
Secondly, I want to do both intention to treat (ITT; all participants randomised to each condition) and per protocol (PP; only participants who did a certain amount of exercise etc) analysis. They both have separate advantages and I would like to include both.
What is the best way/are the best ways to do this? Would I perform a separate MANOVA for each and then do some kind of adjustment like bonferroni? Or include them in the MANOVA as separate groups?
I think I have read somewhere that the same participants should not be used in a MANOVA unless it is a repeated measures but not sure about this.
Lastly, if I wanted to do the above study, with ITT and PP analyses AND wanted to take group measures at 5 points in time and compare these between groups, how would I best go about doing that? I'm thinking some kind of multilevel model, but none of my books cover this, and I don't know if that would be getting out of my depth. Alternatively, could I do a repeated measures MANOVA?
I am working with SPSS.
A lot here I know. As I said, I have read about a fair bit but can't seem to find instructions/recommendations of what kind of test to do in any of my books.
Any help would be very much appreciated.
Thank you muchly guys
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