Help using Base SAS procedures

proc freq - agree option for matched pairs

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Occasional Contributor kc
Occasional Contributor
Posts: 14

proc freq - agree option for matched pairs

I have a health status scale measured at 2 different timepoints (baseline and 1 month) with 5 different response levels (0-4). 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 p-value and not a level-by-level p-value 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 t-test 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

Frequency
Table of hs_BASELINE by hs_1_MONTH
hs_BASELINE hs_1_MONTH
0 1 2 3 4 Total
0
327
55
25
12
17
436
1
236
100
37
17
14
404
2
140
66
42
21
22
291
3
106
39
36
14
21
216
4
62
38
33
30
67
230
Total
871
298
173
94
141
1577
Frequency Missing = 325


 

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.
Super User
Posts: 10,028

Re: proc freq - agree option for matched pairs

Was it repeated measure problem ?

Check PROC CATMOD for contingency table.

Especially the example in its documentation.

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