topic Stratification vs. Adjustment in Statistical Procedures https://communities.sas.com/t5/Statistical-Procedures/Stratification-vs-Adjustment/m-p/175990#M9097 <HTML><HEAD></HEAD><BODY><P>This is more of a general statistical question rather than SAS specific.</P><P></P><P>We run a lot of survival curves on clinical trial data, and we get hazard ratios to accompany those curves.&nbsp; When we make no changes to the data, we get an unadjusted hazard ratio.&nbsp; I have been asked to run stratified and adjusted hazard ratios as well.&nbsp; I know how to code these in SAS, but I have a hard time explaining them.&nbsp; I have asked others in the company, but I'm not getting too far.&nbsp; Can someone clearly explain the difference between stratified and adjusted?</P><P></P><P>I believe stratified is running a bunch of hazard ratios based on different strata (e.g., race, gender, etc.).&nbsp; Then SAS pools those to give a more precise hazard ratio than the unadjusted hazard ratio.&nbsp; Is that correct?&nbsp; If so, great, but I have no idea how to explain adjusted analyses.</P></BODY></HTML> Wed, 28 May 2014 21:03:06 GMT djbateman 2014-05-28T21:03:06Z Stratification vs. Adjustment https://communities.sas.com/t5/Statistical-Procedures/Stratification-vs-Adjustment/m-p/175990#M9097 <HTML><HEAD></HEAD><BODY><P>This is more of a general statistical question rather than SAS specific.</P><P></P><P>We run a lot of survival curves on clinical trial data, and we get hazard ratios to accompany those curves.&nbsp; When we make no changes to the data, we get an unadjusted hazard ratio.&nbsp; I have been asked to run stratified and adjusted hazard ratios as well.&nbsp; I know how to code these in SAS, but I have a hard time explaining them.&nbsp; I have asked others in the company, but I'm not getting too far.&nbsp; Can someone clearly explain the difference between stratified and adjusted?</P><P></P><P>I believe stratified is running a bunch of hazard ratios based on different strata (e.g., race, gender, etc.).&nbsp; Then SAS pools those to give a more precise hazard ratio than the unadjusted hazard ratio.&nbsp; Is that correct?&nbsp; If so, great, but I have no idea how to explain adjusted analyses.</P></BODY></HTML> Wed, 28 May 2014 21:03:06 GMT https://communities.sas.com/t5/Statistical-Procedures/Stratification-vs-Adjustment/m-p/175990#M9097 djbateman 2014-05-28T21:03:06Z