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

Hello,

I have a binary variable (yes/no) and two measuring time (T1 and T2). Thus data are not independant.

I would like to calculate the difference (in percentage) between the proportion of "yes" at T1 and the proportion of "yes" at T2. Moreover i need to calculate the confidence interval of this difference.

I thought it was possible using proc freq (as paired ttest) but i wasn't successufll at getting it to work.

Hoping that you can help me.

Thank you.

 

 

1 ACCEPTED SOLUTION
3 REPLIES 3
FlorianM
Fluorite | Level 6

Thanks a lot for your response.

FreelanceReinh
Jade | Level 19

Later readers of this thread should note:

 

The blog article linked in the accepted solution is about proportions in independent samples. The confidence intervals for a proportion difference in that situation will tend to be too narrow when applied to dependent (paired) samples.

 

A discussion of CIs for the latter situation (including SAS code) can be found in the SESUG 2013 paper SAS® Macros CORR_P and TANGO: Interval Estimation for the Difference between Correlated Proportions ....

hackathon24-white-horiz.png

The 2025 SAS Hackathon has begun!

It's finally time to hack! Remember to visit the SAS Hacker's Hub regularly for news and updates.

Latest Updates

How to Concatenate Values

Learn how use the CAT functions in SAS to join values from multiple variables into a single value.

Find more tutorials on the SAS Users YouTube channel.

SAS Training: Just a Click Away

 Ready to level-up your skills? Choose your own adventure.

Browse our catalog!

Discussion stats
  • 3 replies
  • 5243 views
  • 0 likes
  • 3 in conversation