Could I please get some advice on coding a linear mixed model for looking at between and within subject effect. I have 2 Timepoints (Baseline and 12 weeks Post intervention) and 2 groups (Ex1 and Ex2).

Outcome variable ~ Group*Timepoint + (1|ID) 

I know this will answer the first and second points but I want to run one model so I can answer all three

1. I want to see if there is an interaction between timepoint and group. (i.e after the intervention did the outcome variable improve more in Ex2 than Ex1).

2. I want to see if regardless of group did my outcome variable change after 12 weeks

3. And finally (this is part I am struggling with), within each group did my outcome variable change from Baseline to 12 weeks post?

Outcome variable ~ Group*Timepoint + (1+Timepoint|Group)

OR

Outcome variable ~ Group*Timepoint + (1+Timepoint|Group/ID)

Could I please get some advice on coding a linear mixed model for looking at between and within group effect. I have 2 Timepoints (Baseline and 12 weeks Post intervention) and 2 groups (Ex1 and Ex2).

Outcome variable ~ Group*Timepoint + (1|ID) 

I know this will answer the first and second points but I want to run one model so I can answer all three

1. I want to see if there is an interaction between timepoint and group. (i.e after the intervention did the outcome variable improve more in Ex2 than Ex1).

2. I want to see if regardless of group did my outcome variable change after 12 weeks

3. And finally (this is part I am struggling with), within each group did my outcome variable change from Baseline to 12 weeks post?

Outcome variable ~ Group*Timepoint + (1+Timepoint|Group)

OR

Outcome variable ~ Group*Timepoint + (1+Timepoint|Group/ID)

Could I please get some advice on coding a linear mixed model for looking at between and within subject effect. I have 2 Timepoints (Baseline and 12 weeks Post intervention) and 2 groups (Ex1 and Ex2).

Outcome variable ~ Group*Timepoint + (1|ID)

I know this will answer the first and second points but I want to run one model so I can answer all three

1. I want to see if there is an interaction between timepoint and group. (i.e after the intervention did the outcome variable improve more in Ex2 than Ex1).

2. I want to see if regardless of group did my outcome variable change after 12 weeks

3. And finally (this is part I am struggling with), within each group did my outcome variable change from Baseline to 12weeks post?

Outcome variable ~ Group*Timepoint + (1+Timepoint|Group) OR
Outcome variable ~ Group*Timepoint + (1+Timepoint|Group/ID)

Could I please get some advice on coding a linear mixed model for looking at between and within subject effect. I have 2 Timepoints (Baseline and 12 weeks Post intervention) and 2 groups (Ex1 and Ex2).

Outcome variable ~ Group*Timepoint + (1|ID) 

I know this will answer the first and second points but I want to run one model so I can answer all three

1. I want to see if there is an interaction between timepoint and group. (i.e after the intervention did the outcome variable improve more in Ex2 than Ex1).

2. I want to see if regardless of group did my outcome variable change after 12 weeks

3. And finally (this is part I am struggling with), within each group did my outcome variable change from Baseline to 12 weeks post?

Outcome variable ~ Group*Timepoint + (1+Timepoint|Group)

OR

Outcome variable ~ Group*Timepoint + (1+Timepoint|Group/ID)