BookmarkSubscribeRSS Feed
wfan
Calcite | Level 5

I am puzzled by how PROC PSMATCH calculates the standardized mean differences for matched observations. According to the SAS document (https://documentation.sas.com/doc/en/statug/15.2/statug_psmatch_details25.htm), the standardized deviation for matched observation is pooled (before matching) instead of the matched (after matching). Why does SAS use the before-matching standardized deviation to calculate the after-matching standardized mean differences? This question also applies to weighting.

 

As an example, the table below is from the SAS document example (https://documentation.sas.com/doc/en/statug/15.2/statug_psmatch_examples01.htm). The same standard deviation is used for all observations and weighted observations. Shouldn't the standard deviations be different?

wfan_0-1642097083530.png

Many thanks

SAS Innovate 2025: Save the Date

 SAS Innovate 2025 is scheduled for May 6-9 in Orlando, FL. Sign up to be first to learn about the agenda and registration!

Save the date!

What is ANOVA?

ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.

Find more tutorials on the SAS Users YouTube channel.

Discussion stats
  • 0 replies
  • 1198 views
  • 0 likes
  • 1 in conversation