05032017 03:18 PM
I have a health status scale measured at 2 different timepoints (baseline and 1 month) with 5 different response levels (04). I want to see if there is a statistically significant difference in within group change from baseline to the 1 month time point for each of these response levels. My questions are as follows:
1. Am I using the right code to accomplish this task?
2. If so, which statistics do I report to highlight if the difference is significant?
3. Finally, I think the procedure below gives an overall pvalue and not a levelbylevel pvalue and statistics. How do I test a level by level difference between baseline and 1 month response? Like the difference between response level 0 between baseline and 1 month.
I am running the following proc freq code (analogous to paired ttest for continous variables):
proc freq data=health;
tables hs_BASELINE*hs_1_MONTH / agree norow nocol nopercent;
run;
The result is as follows:
SAS Output


Statistics for Table of hs_BASELINE by hs_1_MONTH 
Test of Symmetry  

Statistic (S)  328.8670 
DF  10 
Pr > S  <.0001 
Kappa Statistics  

Statistic  Value  ASE  95% Confidence Limits  
Simple Kappa  0.1402  0.0139  0.1130  0.1674 
Weighted Kappa  0.2379  0.0171  0.2044  0.2714 
Effective Sample Size = 1577 Frequency Missing = 325 
WARNING: 17% of the data are missing. 
05042017 10:03 AM
Was it repeated measure problem ?
Check PROC CATMOD for contingency table.
Especially the example in its documentation.