topic Re: Miettienen-Nurminen confidence limit for stratified data in SAS Programming

Miettienen-Nurminen confidence limit for stratified data

Smile_to_you — Wed, 05 Oct 2016 23:14:19 GMT

Hello, I have a result dataset from a clinical trial:

obj stratum trt success

1 1 A 1

2 1 B 0

3 2 B 1

......

I want to calculate difference of success rate between treatment A and B, as well as its CL using Miettienen-Nurminen

method stratified by the variable "stratum".

The code I used is

proc freq data=data order=formatted;
tables STRATUM*TRT*sucess/ riskdiff(cl=mn);
ods output RiskDiffCol2=pdiff;
ods output PdiffCLs=pdiffci;
run;

With this code I can only get MN CI within each stratum. I am wondering how I can get overall weighted CI accross stratum?

My SAS version is 9.4

Thanks!

Re: Miettienen-Nurminen confidence limit for stratified data

Ksharp — Thu, 06 Oct 2016 05:43:48 GMT

It looks not so easy. Check:

http://support.sas.com/kb/37/228.html

data have;
input stratum  trt $  success;
cards;
1          A      1
1         B       0
1          A      0
1         B       0
1          A      1
1         B       1
1          A      1
1         B       0
1          A      0
1         B       1
1          A      0
1         B       1
1          A      1
1         B       0
1          A      0
1         B       0
2         B       1
2          A      1
2         B       1
2          A      0
2         B       0
2          A      0
2         B       1
2          A      1
2         B       1
2          A      1
2         B       0
2          A      0
2         B       0
2          A      1
2         B       0
2          A      1
2         B       0
;
run;

proc genmod data=have descend;
 class stratum trt;
 model success=stratum trt/dist=binomial link=identity;
 lsmeans trt/ diff cl ;
 effectplot /clm;
run;

proc catmod data=have;
  response 0 1;
  model success = stratum trt / param=ref clparm;
  contrast "Prob Diff Trt A-B" trt 1  / estimate=parm;
 quit;

Re: Miettienen-Nurminen confidence limit for stratified data

Smile_to_you — Thu, 06 Oct 2016 22:19:08 GMT

Thank you! But I am not sure if it gives us MN confidence limit.

It appears that Proc Freq can do it, but SAS does not provide detailed Syntax.

http://support.sas.com/documentation/cdl/en/procstat/67528/HTML/default/viewer.htm#procstat_freq_details63.htm

Re: Miettienen-Nurminen confidence limit for stratified data

Ksharp — Fri, 07 Oct 2016 07:16:02 GMT

As far as I know, riskdiff is only for 2x2 table, I am not sure if you can get it by including the third way/variable.

Re: Miettienen-Nurminen confidence limit for stratified data

Smile_to_you — Fri, 07 Oct 2016 23:03:15 GMT

I am not sure how SAS can handle with statified CL with proc freq, but this is what it says on the website.