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

Prm5

gender*cage

Prm6

gender*cage2

 

Criteria For Assessing Goodness Of Fit

Criterion

DF

Value

Value/DF

Deviance

9850

10185.6781

1.0341

Scaled Deviance

9850

10185.6781

1.0341

Pearson Chi-Square

9850

9848.8851

0.9999

Scaled Pearson X2

9850

9848.8851

0.9999

Log Likelihood

 

-5092.8391

 

 

Algorithm converged.

 

Analysis Of Initial Parameter Estimates

Parameter

DF

Estimate

Standard Error

Wald 95% Confidence Limits

Chi-Square

Pr > ChiSq

Intercept

1

-1.2130

0.0461

-1.3034

-1.1227

692.24

<.0001

gender

1

0.0962

0.0647

-0.0305

0.2229

2.21

0.1368

cage

1

0.0324

0.0128

0.0073

0.0575

6.42

0.0113

cage2

1

-0.0183

0.0039

-0.0260

-0.0106

21.83

<.0001

gender*cage

1

-0.0043

0.0178

-0.0392

0.0306

0.06

0.8105

gender*cage2

1

0.0037

0.0055

-0.0070

0.0144

0.46

0.4954

Scale

0

1.0000

0.0000

1.0000

1.0000

 

 

 

NOTE:

The scale parameter was held fixed.

 

GEE Model Information

Log Odds Ratio Structure

Fully Parameterized Clusters

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

Parameter

Group

Alpha1

(1, 2)

Alpha2

(1, 3)

Alpha3

(2, 3)

 

Algorithm converged.

 

Analysis Of GEE Parameter Estimates

Empirical Standard Error Estimates

Parameter

Estimate

Standard Error

95% Confidence Limits

Z

Pr > |Z|

Intercept

-1.2135

0.0506

-1.3126

-1.1144

-24.00

<.0001

gender

0.1159

0.0711

-0.0235

0.2553

1.63

0.1033

cage

0.0378

0.0133

0.0118

0.0638

2.85

0.0043

cage2

-0.0175

0.0034

-0.0241

-0.0109

-5.19

<.0001

gender*cage

0.0075

0.0182

-0.0282

0.0433

0.41

0.6795

gender*cage2

0.0039

0.0046

-0.0051

0.0130

0.85

0.3949

Alpha1

3.1528

0.1280

2.9019

3.4037

24.63

<.0001

Alpha2

2.5975

0.1353

2.3323

2.8627

19.20

<.0001

Alpha3

2.9868

0.1236

2.7446

3.2291

24.17

<.0001

 

Wald Statistics For Type 3 GEE Analysis

Source

DF

Chi-Square

Pr > ChiSq

gender

1

2.65

0.1033

cage

1

8.13

0.0043

cage2

1

26.92

<.0001

gender*cage

1

0.17

0.6795

gender*cage2

1

0.72

0.3949

 

Contrast Results for GEE Analysis

Contrast

DF

Chi-Square

Pr > ChiSq

Type

Age X Gender Interaction

2

0.91

0.6356

Wald