https://communities.sas.com/t5/Statistical-Procedures/Confidence-interval-for-the-effect-of-treatment-among-a-certain/m-p/395344#M20644 <P>Hi,&nbsp;</P><P>&nbsp;</P><P>I am running a logistic regression model (a relatively simple one) and want to know if it's possible to obtain a confidence interval for the effect of age among males.</P><P>&nbsp;</P><P>This is my model:&nbsp;</P><P>&nbsp;</P><P>logit(y) = age + male + age*male</P><P>&nbsp;</P><P>where male = 1 if male and male = 0 if female. I am not sure if I need a CONTRAST statement in PROC LOGISTIC. I know I need the variance-covariance matrix, but I am not sure how to obtain it using SAS. However, it would be ideal if I could somehow obtain the 95% CI without having to do the calculations by hand using the variance-covariance matrix.</P> Wed, 13 Sep 2017 00:27:12 GMT corkee 2017-09-13T00:27:12Z https://communities.sas.com/t5/Statistical-Procedures/Confidence-interval-for-the-effect-of-treatment-among-a-certain/m-p/395344#M20644 <P>Hi,&nbsp;</P><P>&nbsp;</P><P>I am running a logistic regression model (a relatively simple one) and want to know if it's possible to obtain a confidence interval for the effect of age among males.</P><P>&nbsp;</P><P>This is my model:&nbsp;</P><P>&nbsp;</P><P>logit(y) = age + male + age*male</P><P>&nbsp;</P><P>where male = 1 if male and male = 0 if female. I am not sure if I need a CONTRAST statement in PROC LOGISTIC. I know I need the variance-covariance matrix, but I am not sure how to obtain it using SAS. However, it would be ideal if I could somehow obtain the 95% CI without having to do the calculations by hand using the variance-covariance matrix.</P> Wed, 13 Sep 2017 00:27:12 GMT https://communities.sas.com/t5/Statistical-Procedures/Confidence-interval-for-the-effect-of-treatment-among-a-certain/m-p/395344#M20644 corkee 2017-09-13T00:27:12Z https://communities.sas.com/t5/Statistical-Procedures/Confidence-interval-for-the-effect-of-treatment-among-a-certain/m-p/395354#M20645 <P>Why not use the ODDSRATIO statement?</P> <P>&nbsp;</P> <P>Maybe this example helps?</P> <P><A href="http://support.sas.com/documentation/cdl/en/statug/68162/HTML/default/viewer.htm#statug_logistic_examples02.htm" target="_blank">http://support.sas.com/documentation/cdl/en/statug/68162/HTML/default/viewer.htm#statug_logistic_examples02.htm</A></P> <P>&nbsp;</P> Wed, 13 Sep 2017 01:22:57 GMT https://communities.sas.com/t5/Statistical-Procedures/Confidence-interval-for-the-effect-of-treatment-among-a-certain/m-p/395354#M20645 Reeza 2017-09-13T01:22:57Z