Marginal Logistic Regression Model for Obesity

Muscatine Coronary Risk Factor Study

 

The GENMOD Procedure

 

Model Information

Data Set

WORK.OBESITY

Distribution

Binomial

Link Function

Logit

Dependent Variable

y

Observations Used

9856

Missing Values

4712

 

Class Level Information

Class

Levels

Values

id

4856

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 ...

occasion

3

1 2 3

 

Response Profile

Ordered
Value

y

Total
Frequency

1

1

2112

2

0

7744

 

PROC GENMOD is modeling the probability that y='1'.

 

Parameter Information

Parameter

Effect

Prm1

Intercept

Prm2

gender

Prm3

cage

Prm4

cage2

 

Criteria For Assessing Goodness Of Fit

Criterion

DF

Value

Value/DF

Deviance

9852

10186.1832

1.0339

Scaled Deviance

9852

10186.1832

1.0339

Pearson Chi-Square

9852

9848.5977

0.9997

Scaled Pearson X2

9852

9848.5977

0.9997

Log Likelihood

 

-5093.0916

 

 

Algorithm converged.

 

Analysis Of Initial Parameter Estimates

Parameter

DF

Estimate

Standard Error

Wald 95% Confidence Limits

Chi-Square

Pr > ChiSq

Intercept

1

-1.2275

0.0410

-1.3078

-1.1472

897.53

<.0001

gender

1

0.1246

0.0492

0.0281

0.2211

6.41

0.0114

cage

1

0.0303

0.0089

0.0128

0.0477

11.58

0.0007

cage2

1

-0.0164

0.0027

-0.0218

-0.0111

36.25

<.0001

Scale

0

1.0000

0.0000

1.0000

1.0000

 

 

 

NOTE:

The scale parameter was held fixed.

 

GEE Model Information

Log Odds Ratio Structure

Replicated Z-Matrix

Within-Subject Effect

occasion (3 levels)

Subject Effect

id (4856 levels)

Number of Clusters

4856

Clusters With Missing Values

3086

Correlation Matrix Dimension

3

Maximum Cluster Size

3

Minimum Cluster Size

1

 

Log Odds Ratio Parameter Information

Cluster Pair

Alpha1

Alpha2

(1, 2)

1

0

(1, 3)

0

1

(2, 3)

1

0

 

Algorithm converged.

 

Analysis Of GEE Parameter Estimates

Empirical Standard Error Estimates

Parameter

Estimate

Standard Error

95% Confidence Limits

Z

Pr > |Z|

Intercept

-1.2270

0.0477

-1.3205

-1.1335

-25.72

<.0001

gender

0.1445

0.0627

0.0216

0.2674

2.31

0.0212

cage

0.0416

0.0091

0.0238

0.0594

4.58

<.0001

cage2

-0.0156

0.0023

-0.0201

-0.0111

-6.77

<.0001

Alpha1

3.0684

0.0957

2.8809

3.2559

32.07

<.0001

Alpha2

2.5929

0.1353

2.3278

2.8581

19.17

<.0001

 

Wald Statistics For Type 3 GEE Analysis

Source

DF

Chi-Square

Pr > ChiSq

gender

1

5.31

0.0212

cage

1

20.97

<.0001

cage2

1

45.80

<.0001