SAS应用_医学统计学的例题程序及其结果,学习SAS的必备资料.
源代码在线查看： 例16-03计算结果.lst
The SAS System 21:18 Tuesday, April 2, 2002 27
The PHREG Procedure
Data Set: WORK.EX16_3
Dependent Variable: T
Censoring Variable: Y
Censoring Value(s): 0
Ties Handling: DISCRETE
Summary of the Number of Event and Censored Values
Percent
Stratum I Total Event Censored Censored
1 1 3 1 2 66.67
2 2 3 1 2 66.67
3 3 3 1 2 66.67
4 4 3 1 2 66.67
5 5 3 1 2 66.67
6 6 3 1 2 66.67
7 7 3 1 2 66.67
8 8 3 1 2 66.67
9 9 3 1 2 66.67
10 10 3 1 2 66.67
11 11 3 1 2 66.67
12 12 3 1 2 66.67
13 13 3 1 2 66.67
14 14 3 1 2 66.67
15 15 3 1 2 66.67
16 16 3 1 2 66.67
17 17 3 1 2 66.67
18 18 3 1 2 66.67
19 19 3 1 2 66.67
20 20 3 1 2 66.67
21 21 3 1 2 66.67
22 22 3 1 2 66.67
23 23 3 1 2 66.67
24 24 3 1 2 66.67
25 25 3 1 2 66.67
-------------------------------------------------------------------
Total 75 25 50 66.67
Step 1: Variable X2 is entered. The model contains the following explanatory variables.
X2
The SAS System 21:18 Tuesday, April 2, 2002 28
The PHREG Procedure
Testing Global Null Hypothesis: BETA=0
Without With
Criterion Covariates Covariates Model Chi-Square
-2 LOG L 54.931 39.023 15.908 with 1 DF (p=0.0001)
Score . . 15.135 with 1 DF (p=0.0001)
Wald . . 9.890 with 1 DF (p=0.0017)
Step 2: Variable X3 is entered. The model contains the following explanatory variables.
X2 X3
Testing Global Null Hypothesis: BETA=0
Without With
Criterion Covariates Covariates Model Chi-Square
-2 LOG L 54.931 27.741 27.189 with 2 DF (p=0.0001)
Score . . 21.609 with 2 DF (p=0.0001)
Wald . . 10.764 with 2 DF (p=0.0046)
Step 3: Variable X6 is entered. The model contains the following explanatory variables.
X2 X3 X6
Testing Global Null Hypothesis: BETA=0
Without With
Criterion Covariates Covariates Model Chi-Square
-2 LOG L 54.931 22.641 32.290 with 3 DF (p=0.0001)
Score . . 26.069 with 3 DF (p=0.0001)
Wald . . 10.958 with 3 DF (p=0.0120)
Step 4: Variable X4 is entered. The model contains the following explanatory variables.
X2 X3 X4 X6
The SAS System 21:18 Tuesday, April 2, 2002 29
The PHREG Procedure
Testing Global Null Hypothesis: BETA=0
Without With
Criterion Covariates Covariates Model Chi-Square
-2 LOG L 54.931 16.112 38.819 with 4 DF (p=0.0001)
Score . . 28.397 with 4 DF (p=0.0001)
Wald . . 8.962 with 4 DF (p=0.0620)
Step 5: Variable X1 is entered. The model contains the following explanatory variables.
X1 X2 X3 X4 X6
Testing Global Null Hypothesis: BETA=0
Without With
Criterion Covariates Covariates Model Chi-Square
-2 LOG L 54.931 12.901 42.029 with 5 DF (p=0.0001)
Score . . 29.069 with 5 DF (p=0.0001)
Wald . . 7.782 with 5 DF (p=0.1687)
Step 6: Variable X1 is removed. The model contains the following explanatory variables.
X2 X3 X4 X6
Testing Global Null Hypothesis: BETA=0
Without With
Criterion Covariates Covariates Model Chi-Square
-2 LOG L 54.931 16.112 38.819 with 4 DF (p=0.0001)
Score . . 28.397 with 4 DF (p=0.0001)
Wald . . 8.962 with 4 DF (p=0.0620)
NOTE: Model building terminates because the variable to be entered is the variable that was
removed in the last step.
The SAS System 21:18 Tuesday, April 2, 2002 30
The PHREG Procedure
Analysis of Maximum Likelihood Estimates
Parameter Standard Wald Pr > Risk
Variable DF Estimate Error Chi-Square Chi-Square Ratio
X2 1 1.486914 0.55065 7.29158 0.0069 4.423
X3 1 1.916646 0.94435 4.11921 0.0424 6.798
X4 1 -3.764052 1.82510 4.25341 0.0392 0.023
X6 1 3.632112 1.86572 3.78988 0.0516 37.793
Summary of Stepwise Procedure
Variable Number Score Wald Pr >
Step Entered Removed In Chi-Square Chi-Square Chi-Square
1 X2 1 15.1348 . 0.0001
2 X3 2 11.2238 . 0.0008
3 X6 3 4.7753 . 0.0289
4 X4 4 4.0904 . 0.0431
5 X1 5 2.7462 . 0.0975
6 X1 4 . 0.9080 0.3406
