Marginal proportional odds regression model for global impression scale
Arthritis Clinical Trial

The GENMOD Procedure

Model Information
Data Set WORK.ARTHRITIS
Distribution Multinomial
Link Function Cumulative Logit
Dependent Variable y

Number of Observations Read 1194
Number of Observations Used 1194

Class Level Information
Class Levels Values
id 303 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 ...

Response Profile
Ordered
Value		 y Total
Frequency
1 1 86
2 2 332
3 3 478
4 4 240
5 5 58


PROC GENMOD is modeling the probabilities of levels of y having LOWER Ordered Values in the response profile table. One way to change this to model the probabilities of HIGHER Ordered Values is to specify the DESCENDING option in the PROC statement.

Parameter Information
Parameter Effect
Prm1 trt
Prm2 sqrtmonth
Prm3 trt*sqrtmonth

Algorithm converged.

GEE Model Information
Correlation Structure Independent
Subject Effect id (303 levels)
Number of Clusters 303
Correlation Matrix Dimension 4
Maximum Cluster Size 4
Minimum Cluster Size 1

Algorithm converged.

GEE Fit Criteria
QIC 3261.1733
QICu 3254.2892

Analysis Of GEE Parameter Estimates
Empirical Standard Error Estimates
Parameter Estimate Standard Error 95% Confidence Limits Z Pr > |Z|
Intercept1 -3.1902 0.1994 -3.5811 -2.7994 -16.00 <.0001
Intercept2 -1.2042 0.1523 -1.5027 -0.9057 -7.91 <.0001
Intercept3 0.5736 0.1464 0.2867 0.8606 3.92 <.0001
Intercept4 2.4770 0.1995 2.0860 2.8680 12.42 <.0001
trt 0.0714 0.1975 -0.3158 0.4586 0.36 0.7178
sqrtmonth 0.2481 0.0613 0.1279 0.3683 4.05 <.0001
trt*sqrtmonth 0.2354 0.0883 0.0623 0.4086 2.66 0.0077

Wald Statistics For Type 3 GEE Analysis
Source DF Chi-Square Pr > ChiSq
trt 1 0.13 0.7178
sqrtmonth 1 16.37 <.0001
trt*sqrtmonth 1 7.10 0.0077