https://communities.sas.com/t5/Statistical-Procedures/Sample-size-calculation-for-Poisson-regression/m-p/937110#M46764 <P>I think the way to do this is to use PROC POWER with a CUSTOM statement. See this example:&nbsp;<A href="https://go.documentation.sas.com/doc/en/statug/15.2/statug_power_examples17.htm" target="_blank">SAS Help Center: Logistic Regression Using the CUSTOM Statement</A>. The linked example is for logistic regression, but you can adapt the approach for other generalized linear models, like a Poisson model.&nbsp;</P> Thu, 25 Jul 2024 13:54:22 GMT Mike_N 2024-07-25T13:54:22Z https://communities.sas.com/t5/Statistical-Procedures/Sample-size-calculation-for-Poisson-regression/m-p/937067#M46762 <P>Is there any easy way to calculate sample size for a Poisson model with offset? I am planning a cohort study with recurrence short term outcome. That is, one participant can get the outcome multiple times during the follow-up period.</P> Thu, 25 Jul 2024 00:29:06 GMT https://communities.sas.com/t5/Statistical-Procedures/Sample-size-calculation-for-Poisson-regression/m-p/937067#M46762 BayzidurRahman 2024-07-25T00:29:06Z https://communities.sas.com/t5/Statistical-Procedures/Sample-size-calculation-for-Poisson-regression/m-p/937110#M46764 <P>I think the way to do this is to use PROC POWER with a CUSTOM statement. See this example:&nbsp;<A href="https://go.documentation.sas.com/doc/en/statug/15.2/statug_power_examples17.htm" target="_blank">SAS Help Center: Logistic Regression Using the CUSTOM Statement</A>. The linked example is for logistic regression, but you can adapt the approach for other generalized linear models, like a Poisson model.&nbsp;</P> Thu, 25 Jul 2024 13:54:22 GMT https://communities.sas.com/t5/Statistical-Procedures/Sample-size-calculation-for-Poisson-regression/m-p/937110#M46764 Mike_N 2024-07-25T13:54:22Z https://communities.sas.com/t5/Statistical-Procedures/Sample-size-calculation-for-Poisson-regression/m-p/937178#M46765 You also could check PROC GLMPOWER for the MIXED model. Fri, 26 Jul 2024 00:58:48 GMT https://communities.sas.com/t5/Statistical-Procedures/Sample-size-calculation-for-Poisson-regression/m-p/937178#M46765 Ksharp 2024-07-26T00:58:48Z https://communities.sas.com/t5/Statistical-Procedures/Sample-size-calculation-for-Poisson-regression/m-p/937336#M46767 <P>Hi, that looks like an easier option but I cannot find options to specify the Poisson model options such as, link=, offset=, dist= etc.</P> Sat, 27 Jul 2024 00:31:12 GMT https://communities.sas.com/t5/Statistical-Procedures/Sample-size-calculation-for-Poisson-regression/m-p/937336#M46767 BayzidurRahman 2024-07-27T00:31:12Z