Hi all, I want to estimate the sample size for a non-inferiority test of paired proportions. There is an excellent discussion on this in PASS documentation: http://ncss.wpengine.netdna-cdn.com/wp-content/themes/ncss/pdf/Procedures/PASS/Non-Inferiority_Tests_for_Two_Correlated_Proportions.pdf I know that in SAS there is PAIREDFREQ in PROC POWER, but  it seems that there is no straight forward solution for this non-inferiority problem. Can anyone shed lights on how to solve it in SAS?    Thanks in advance!  Hu ... View more

It is fine to define the following scalars in SAS: x1=1/sqrt(5); x2=2/5; x3=6**3; however, syntax errors appear when one tries to define a vector like this: proc iml; x={1/sqrt(5) 2/5 6**3}; I never experienced a similar problem in Matlab which I use more frequently than SAS. It seems that there is a similar problem in SAS data step as well. I know that probably one rarely has to use arithmetic operators in defining a matrix or in data steps. But I am curious whether this is an easy solution for this. ... View more

I encountered a problem while I was studying SAS programming for clinical trials. I will just paste the problem here: " Using dataset DOSES, create a report showing all patients who changed dose during the study, and their actual dose at each visit. In this report indicate the extent of dose adjustment by creating a variable called DOSEADJ which takes the values N (normal) if dose remains the same as at visit 1 R (reduced) if the dose is less than the previous dose P (remains reduced) if the dose is the same as the previous dose, but the previous dose was reduced compared with visit 1 For example, patients 1 & 6 would appear in the report as below, but patients 4 & 5 would not be reported. Note PATIENT uniquely identifies the patient. PATIENT    VISIT    ACTLDOSE    DOSEADJ      1       1        32          N                2        32          N                3        16          R                4        16          P                5        16          P       6       1        32          N                2        16          R                3         4           R " Suppose the raw data is just like the first three columns of the data shown above, how exactly can I generate the fourth column (DOSEADJ)? as required? I thought of using 'retain' and 'first.patient' etc, but have not been able to produce the code which can do the job. Thanks!   ... View more