https://communities.sas.com/t5/SAS-Procedures/Sample-size-for-a-logistic-regression-polytomic-multifactorial/m-p/35498#M8766 I have to calculate a sample size for a logistic regression polytomic multifactorial.<BR /> The ordinal response has 3 modalities (mild, moderate, severe)<BR /> There are 9 binary (yes/no) variables to include in the model and 1 variable with 3 modalities.<BR /> Thanks by advance. Thu, 31 Jul 2008 16:22:29 GMT Cyril_FR 2008-07-31T16:22:29Z https://communities.sas.com/t5/SAS-Procedures/Sample-size-for-a-logistic-regression-polytomic-multifactorial/m-p/35498#M8766 I have to calculate a sample size for a logistic regression polytomic multifactorial.<BR /> The ordinal response has 3 modalities (mild, moderate, severe)<BR /> There are 9 binary (yes/no) variables to include in the model and 1 variable with 3 modalities.<BR /> Thanks by advance. Thu, 31 Jul 2008 16:22:29 GMT https://communities.sas.com/t5/SAS-Procedures/Sample-size-for-a-logistic-regression-polytomic-multifactorial/m-p/35498#M8766 Cyril_FR 2008-07-31T16:22:29Z https://communities.sas.com/t5/SAS-Procedures/Sample-size-for-a-logistic-regression-polytomic-multifactorial/m-p/35499#M8767 I think that the PROC SAS to do that does not exist yet but i found an article (http://www.childrens-mercy.org/stats/weblog2004/OrdinalLogistic.asp) where there is the formula to calculate the sample size. Wed, 06 Aug 2008 16:02:30 GMT https://communities.sas.com/t5/SAS-Procedures/Sample-size-for-a-logistic-regression-polytomic-multifactorial/m-p/35499#M8767 Cyril_FR 2008-08-06T16:02:30Z