https://communities.sas.com/t5/SAS-Customer-Intelligence/HR-95-CL-is-different-depending-on-3-groups-versus-2-groups-for/m-p/823179#M1817 Isn't the hazard ratio different because the models themselves are different? The reference group is the same, but the variable has 3 levels in one analysis and 2 in another. If a group of participants is omitted from one of the models, there will be a new estimates of the model parameters. Wed, 13 Jul 2022 17:26:08 GMT svh 2022-07-13T17:26:08Z https://communities.sas.com/t5/SAS-Customer-Intelligence/HR-95-CL-is-different-depending-on-3-groups-versus-2-groups-for/m-p/823162#M1816 Wed, 13 Jul 2022 16:11:36 GMT https://communities.sas.com/t5/SAS-Customer-Intelligence/HR-95-CL-is-different-depending-on-3-groups-versus-2-groups-for/m-p/823162#M1816 jim_l51 2022-07-13T16:11:36Z https://communities.sas.com/t5/SAS-Customer-Intelligence/HR-95-CL-is-different-depending-on-3-groups-versus-2-groups-for/m-p/823179#M1817 Isn't the hazard ratio different because the models themselves are different? The reference group is the same, but the variable has 3 levels in one analysis and 2 in another. If a group of participants is omitted from one of the models, there will be a new estimates of the model parameters. Wed, 13 Jul 2022 17:26:08 GMT https://communities.sas.com/t5/SAS-Customer-Intelligence/HR-95-CL-is-different-depending-on-3-groups-versus-2-groups-for/m-p/823179#M1817 svh 2022-07-13T17:26:08Z