https://communities.sas.com/t5/Statistical-Procedures/Power-calculation-for-multicategorical-predictor-in-longitudinal/m-p/828473#M41011 <P>I'm curious if anyone has thoughts about how to set up a power simulation. I have a sample of 70 people who have completed 12 sessions of therapy, which consists of 5 different skill modules delivered in a random order. With proc mixed, I used an indicator variable representing the skill modules as a predictor of continuous depression symptoms at each session. The Type 3 test of fixed effects for the indicator variable was significant - specifically, depression was significantly higher during one module compared to the others. I'm not sure, though, how to set up a simulation with a multicategorical predictor since SAS seems to calculate the Type 3 tests automatically and separately from the modeling input. For reference, I'm most familiar with Lane and Hennes' power code, which covers continuous and binary predictors but not categorical ones:&nbsp;<A href="https://journals.sagepub.com/doi/suppl/10.1177/0265407517710342" target="_blank" rel="noopener">https://journals.sagepub.com/doi/suppl/10.1177/0265407517710342</A></P> Fri, 12 Aug 2022 14:33:08 GMT Matt_Southward 2022-08-12T14:33:08Z https://communities.sas.com/t5/Statistical-Procedures/Power-calculation-for-multicategorical-predictor-in-longitudinal/m-p/828473#M41011 <P>I'm curious if anyone has thoughts about how to set up a power simulation. I have a sample of 70 people who have completed 12 sessions of therapy, which consists of 5 different skill modules delivered in a random order. With proc mixed, I used an indicator variable representing the skill modules as a predictor of continuous depression symptoms at each session. The Type 3 test of fixed effects for the indicator variable was significant - specifically, depression was significantly higher during one module compared to the others. I'm not sure, though, how to set up a simulation with a multicategorical predictor since SAS seems to calculate the Type 3 tests automatically and separately from the modeling input. For reference, I'm most familiar with Lane and Hennes' power code, which covers continuous and binary predictors but not categorical ones:&nbsp;<A href="https://journals.sagepub.com/doi/suppl/10.1177/0265407517710342" target="_blank" rel="noopener">https://journals.sagepub.com/doi/suppl/10.1177/0265407517710342</A></P> Fri, 12 Aug 2022 14:33:08 GMT https://communities.sas.com/t5/Statistical-Procedures/Power-calculation-for-multicategorical-predictor-in-longitudinal/m-p/828473#M41011 Matt_Southward 2022-08-12T14:33:08Z https://communities.sas.com/t5/Statistical-Procedures/Power-calculation-for-multicategorical-predictor-in-longitudinal/m-p/828557#M41016 <P>I remembered&nbsp;<a href="https://communities.sas.com/t5/user/viewprofilepage/user-id/13684">@Rick_SAS</a>&nbsp; wrote a blog about this topic before .</P> Sat, 13 Aug 2022 09:58:20 GMT https://communities.sas.com/t5/Statistical-Procedures/Power-calculation-for-multicategorical-predictor-in-longitudinal/m-p/828557#M41016 Ksharp 2022-08-13T09:58:20Z https://communities.sas.com/t5/Statistical-Procedures/Power-calculation-for-multicategorical-predictor-in-longitudinal/m-p/828559#M41017 <P>The Lane and Hennes paper appears to be behind a paywayll, so cannot access.</P> <P>&nbsp;</P> <P>Show your PROC MIXED code. I<SPAN>t is not clear how you are handling the longitudinal aspect of the design. Also, sample data is always appreciated.</SPAN></P> Sat, 13 Aug 2022 10:22:13 GMT https://communities.sas.com/t5/Statistical-Procedures/Power-calculation-for-multicategorical-predictor-in-longitudinal/m-p/828559#M41017 Rick_SAS 2022-08-13T10:22:13Z