Which statistical test to use

#1
Hello i have a question which statistical test to use

Hello

I really need some help which test to use.

My research question is: Does mindfulness have a moderating influence on the relationship between rumination and marijuana use. The covariates that are used are depressive symptoms and sex. All four continual variables (minfulness, rumination, marijuana use and depressive symptoms) are ask in a follow up three months later. Which test is best to use if i want to know if mindfulness is a moderator when using two different measurement moments?

Thanks in advance,

David
 

Karabiner

TS Contributor
#2
I do not understand what you mean by "follow-up three months later". Seemingly, all variables were measured at the same time. Or do you mean there were repeated measures, each variable was measured twice?

Please explain your research design. How was the sample obtained, how large is your sample, when were variables measured?

With kind regards

Karabiner
 
#3
Thanks for your reply.

Yes i should have explained it better. With a follow-up i meant repeated measures, each variable was measured twice. The data will be obtained through a questionnaire and the first measurements will start coming month. The plan is to have at least 200 participants. Do i just need to merge the two measure moments of each variable into one unit and than do a sort of regression analyses, or is there a better way?

With kind regards

David
 

Karabiner

TS Contributor
#4
It is of course very useful to have longitudinal data. Since I do not know the theoretical context, I only can guess what could be useful here. For example, two separate cross-sectional moderator analyses (one for t1 data, one for t2 data), using regression. Or, whether change in marijuana use between t1 and t2 is associated with change in rumination [or with level of rumination at t1?], and whether this association is moderated by level of mindfulness (repeated measures ANOVA). Structural equation models might also be useful for such research designs, but unfortunately I am not familiar with this approach.

With kind regards

Karabiner
 
#5
Do you mean it as just two different approaches of analyzing the data. Or do you mean that they should follow each other up( first the regression analyses and then the repeated measures ANOVA)?