BookmarkSubscribeRSS Feed
🔒 This topic is solved and locked. Need further help from the community? Please sign in and ask a new question.
MRB3855
Fluorite | Level 6

Good day All: Suppose I have the data (x_data) below, and further suppose I want to calculate  confidence intervals for the difference of two binomial proportions (treat A vs treat B for each trial, respectively) via proc freq as below:

proc freq data=x_data;
by trial;
tables treat*outcome /riskdiff(cl=(exact));
weight count;
exact riskdiff;
run;

proc freq data=x_data;
by trial;
tables treat*outcome /riskdiff(cl=(exact));
weight count;
exact riskdiff(method=fmscore);
run;

trial       treat     outcome count

1Ax56
1Ay14
1Bx48
1By32
2Ax9
2Ay1
2Bx3
2By7
3Ax10
3Ay0
3Bx0
3By20

I expected to get different results from the two different procedures, but I don't. The confidence intervals are exactly the same. My understanding is the former should use the Santner-Snell method ("By default, PROC FREQ uses the unstandardized risk difference as the test statistic in the confidence limit computations.") and the latter should use the Chan-Zhang method ("If you specify the RISKDIFF(METHOD=FMSCORE) option, the procedure uses the Farrington-Manning score statistic (Chan and Zhang 1999).").

What gives? BTW, I'm currently using SAS 9.4 TS Level 1M5.  

Thanks

 
1 ACCEPTED SOLUTION

Accepted Solutions
MRB3855
Fluorite | Level 6

Ah, I've found the problem (via a careful read of log file). Stat v 14.3 switches the default from previous versions.

From the log file: 

NOTE: The default method for EXACT RISKDIFF is now METHOD=SCORE. To use the previous default
      method (in SAS/STAT 14.2 and earlier releases), you can specify EXACT
      RISKDIFF(METHOD=NOSCORE).

Problem solved!

As you were 😉   

View solution in original post

1 REPLY 1
MRB3855
Fluorite | Level 6

Ah, I've found the problem (via a careful read of log file). Stat v 14.3 switches the default from previous versions.

From the log file: 

NOTE: The default method for EXACT RISKDIFF is now METHOD=SCORE. To use the previous default
      method (in SAS/STAT 14.2 and earlier releases), you can specify EXACT
      RISKDIFF(METHOD=NOSCORE).

Problem solved!

As you were 😉   

sas-innovate-2024.png

Available on demand!

Missed SAS Innovate Las Vegas? Watch all the action for free! View the keynotes, general sessions and 22 breakouts on demand.

 

Register now!

Mastering the WHERE Clause in PROC SQL

SAS' Charu Shankar shares her PROC SQL expertise by showing you how to master the WHERE clause using real winter weather data.

Find more tutorials on the SAS Users YouTube channel.

Discussion stats
  • 1 reply
  • 3938 views
  • 0 likes
  • 1 in conversation