-------------------------------------------------------------------------------------------------------------
      name:  <unnamed>
       log:  C:\MyDocs\MPH\LectureNotes\ClassDoLogData\logistic regression\proportions.log
  log type:  text
 opened on:   9 Feb 2011, 11:06:24

. * proportions.log
. *
. * Illustrate Wald, Wilson and exact confidence intervals
. *
. use proportions.dta

. list

     +-----------------+
     | fate   patients |
     |-----------------|
  1. |    0         10 |
  2. |    1         10 |
     +-----------------+

. ci fate [freq = patients], binomial wald

                                                         -- Binomial Wald ---
    Variable |        Obs        Mean    Std. Err.       [95% Conf. Interval]
-------------+---------------------------------------------------------------
        fate |         20          .5    .1118034        .2808694    .7191306

. ci fate [freq = patients], binomial wilson

                                                         ------ Wilson ------
    Variable |        Obs        Mean    Std. Err.       [95% Conf. Interval]
-------------+---------------------------------------------------------------
        fate |         20          .5    .1118034         .299298     .700702

. replace patients = 18 in 1
(1 real change made)

. replace patients = 2 in 2
(1 real change made)

. list

     +-----------------+
     | fate   patients |
     |-----------------|
  1. |    0         18 |
  2. |    1          2 |
     +-----------------+

. ci fate [freq = patients], binomial wald

                                                         -- Binomial Wald ---
    Variable |        Obs        Mean    Std. Err.       [95% Conf. Interval]
-------------+---------------------------------------------------------------
        fate |         20          .1     .067082               0    .2314784*

(*) The Wald interval was clipped at the lower endpoint

. ci fate [freq = patients], binomial wilson

                                                         ------ Wilson ------
    Variable |        Obs        Mean    Std. Err.       [95% Conf. Interval]
-------------+---------------------------------------------------------------
        fate |         20          .1     .067082        .0278665    .3010336

. return list

scalars:
                 r(ub) =  .3010336452284873
                 r(lb) =  .0278664812137682
                 r(se) =  .0670820393249937
               r(mean) =  .1
                  r(N) =  20

. display r(ub)
.30103365

. log close
      name:  <unnamed>
       log:  C:\MyDocs\MPH\LectureNotes\ClassDoLogData\logistic regression\proportions.log
  log type:  text
 closed on:   9 Feb 2011, 11:06:24
-------------------------------------------------------------------------------------------------------------