Chapter 11, Section 11.3.2

 

Study of Risk Factors for Coronary Heart Disease (CHD)

Loglinear (Poisson) Regression Model of CHD on Smoking

 

use "chd.dta"

 

gen logpyrs=log(pyrs)

 

glm  chd  smoke, family(poisson) link(log) offset(logpyrs)

 

Iteration 0:   log likelihood =   -84.1921  

Iteration 1:   log likelihood = -79.847801  

Iteration 2:   log likelihood = -79.844047  

Iteration 3:   log likelihood = -79.844047  

 

Generalized linear models                          No. of obs      =        16

Optimization     : ML                              Residual df     =        14

                                                   Scale parameter =         1

Deviance         =  89.38192792                    (1/df) Deviance =  6.384423

Pearson          =  104.2445013                    (1/df) Pearson  =  7.446036

 

Variance function: V(u) = u                        [Poisson]

Link function    : g(u) = ln(u)                    [Log]

 

                                                   AIC             =  10.23051

Log likelihood   = -79.84404706                    BIC             =  50.56569

 

------------------------------------------------------------------------------

             |                 OIM

         chd |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]

-------------+----------------------------------------------------------------

       smoke |   .0317543   .0056242     5.65   0.000     .0207311    .0427775

       _cons |  -4.799334     .08852   -54.22   0.000     -4.97283   -4.625838

     logpyrs |   (offset)

------------------------------------------------------------------------------

 

 

 

Loglinear (Poisson) Regression Model of CHD on Smoking , Behavior Type and Blood Pressure

 

glm chd smoke behavior bp,family(poisson) link(log) offset(logpyrs)

 

Iteration 0:   log likelihood =   -46.7864  

Iteration 1:   log likelihood = -45.775549  

Iteration 2:   log likelihood = -45.772957  

Iteration 3:   log likelihood = -45.772957  

 

Generalized linear models                          No. of obs      =        16

Optimization     : ML                              Residual df     =        12

                                                   Scale parameter =         1

Deviance         =    21.239747                    (1/df) Deviance =  1.769979

Pearson          =  22.14547393                    (1/df) Pearson  =  1.845456

 

Variance function: V(u) = u                        [Poisson]

Link function    : g(u) = ln(u)                    [Log]

 

                                                   AIC             =   6.22162

Log likelihood   = -45.77295661                    BIC             = -12.03132

 

------------------------------------------------------------------------------

             |                 OIM

         chd |      Coef.   Std. Err.      z    P>|z|     [95% Conf. Interval]

-------------+----------------------------------------------------------------

       smoke |   .0273441   .0056142     4.87   0.000     .0163404    .0383477

    behavior |   .7525546    .136202     5.53   0.000     .4856035    1.019506

          bp |   .7533765   .1292403     5.83   0.000     .5000702    1.006683

       _cons |  -5.420153   .1308135   -41.43   0.000    -5.676543   -5.163763

     logpyrs |   (offset)

------------------------------------------------------------------------------