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alotaibifm
Calcite | Level 5

Hi, 

 

I'm trying to run a proc SURVEYlogistic for a complex data, but the output looks weird. anyone has an idea what do those numbers mean? Especially the one highlighted with red. 

 

The SURVEYLOGISTIC Procedure

Model Information

Data Set

WORK.N15

 

Response Variable

Antibiotic

 

Number of Response Levels

2

 

Stratum Variable

VARSTR

VARIANCE ESTIMATION STRATUM - 2015

Number of Strata

165

 

Cluster Variable

VARPSU

VARIANCE ESTIMATION PSU - 2015

Number of Clusters

349

 

Weight Variable

PERWT

FINAL PERSON WEIGHT, 2015

Model

Binary Logit

 

Optimization Technique

Fisher's Scoring

 

Variance Adjustment

Degrees of Freedom (DF)

 

 

Variance Estimation

Method

Taylor Series

Missing Levels

Included (MISSING)

Variance Adjustment

Degrees of Freedom (DF)

 

Number of Observations Read

23363

Number of Observations Used

23028

Sum of Weights Read

2.5812E8

Sum of Weights Used

2.5812E8

 

Response Profile

Ordered
Value

Antibiotic

Total
Frequency

Total
Weight

1

No

21546

239733598

2

Yes

1482

18390178

 

 

Model Fit Statistics

Criterion

Intercept Only

Intercept and
Covariates

AIC

132597682

131164140

SC

132597690

131164156

-2 Log L

132597680

131164136

 

Testing Global Null Hypothesis: BETA=0

Test

Chi-Square

DF

Pr > ChiSq

Likelihood Ratio

1433543.99

1

<.0001

Score

757520.937

1

<.0001

Wald

71303.0062

1

<.0001

 

Analysis of Maximum Likelihood Estimates

Parameter

DF

Estimate

Standard
Error

Wald
Chi-Square

Pr > ChiSq

Intercept

1

-30.8434

0.0911

114655.453

<.0001

PPI

1

14.1581

0.0530

71303.0062

<.0001

 

Odds Ratio Estimates

Effect

Point Estimate

95% Wald
Confidence Limits

PPI

>999.999

>999.999

>999.999

 

 

Association of Predicted Probabilities and Observed
Responses

Percent Concordant

4.0

Somers' D

0.040

Percent Discordant

0.0

Gamma

1.000

Percent Tied

96.0

Tau-a

0.005

Pairs

31931172

c

0.520

4 REPLIES 4
SAS_Rob
SAS Employee

Are there any messages in the LOG regarding convergence?

 

Typically with coefficient estimates that large and correspondingly small standard errors, there are convergence issues.  It seems like as well that your weights are extremely large.  Have you tried normalizing them?

alotaibifm
Calcite | Level 5

Here is the Log description. No, I haven't normalized the weight. 

 


NOTE: PROC SURVEYLOGISTIC is modeling the probability that Antibiotic='Yes'.
NOTE: Convergence criterion (GCONV=1E-8) satisfied.
NOTE: Only one cluster in a stratum. The estimate of variance will omit this stratum.
NOTE: Only one cluster in a stratum. The estimate of variance will omit this stratum.
NOTE: PROCEDURE SURVEYLOGISTIC used (Total process time):
real time 0.20 seconds
cpu time 0.14 seconds

 

 

SAS_Rob
SAS Employee

Given the large disparity between the sample size and the sum of the weights, you might try normalizing the weights and see if the results make more sense.

alotaibifm
Calcite | Level 5

Do you have any article or thread about data normalization? I haven't done this procedure before. I'm sorry if this is a basic question. 

I will try to do that and see what will happen. 

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