https://communities.sas.com/t5/SAS-Procedures/How-to-determine-the-accrual-time/m-p/58190#M16263 Hi renzhn,<BR /> <BR /> For sample size calculation, what are your null and alternative hypothesis? Mon, 27 Jul 2009 16:21:00 GMT statsplank 2009-07-27T16:21:00Z https://communities.sas.com/t5/SAS-Procedures/How-to-determine-the-accrual-time/m-p/58189#M16262 I am trying to use SAS to estimate the sample size of survival analysis.<BR /> <BR /> This clinical trial has 1 year time to recruit the patients, 1 year to treat them and 2 years followup time. All people are expected to participate 3 years research(1 year treatment+ 2years followup). What accrual time should I use?<BR /> <BR /> Can I use following values to do the calculation:<BR /> accrual time =0 <BR /> follow up time=3<BR /> <BR /> Thank you. Fri, 24 Jul 2009 02:07:46 GMT https://communities.sas.com/t5/SAS-Procedures/How-to-determine-the-accrual-time/m-p/58189#M16262 deleted_user 2009-07-24T02:07:46Z https://communities.sas.com/t5/SAS-Procedures/How-to-determine-the-accrual-time/m-p/58190#M16263 Hi renzhn,<BR /> <BR /> For sample size calculation, what are your null and alternative hypothesis? Mon, 27 Jul 2009 16:21:00 GMT https://communities.sas.com/t5/SAS-Procedures/How-to-determine-the-accrual-time/m-p/58190#M16263 statsplank 2009-07-27T16:21:00Z