Many Sample Logrank Test Example

            
          
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*        Logrank test for many group survival difference      *
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insheet using  http://hedwig.mgh.harvard.edu/biostatistics/sites/default/files/public/education/tmp_sample_data.csv

stset recurr_day, failure(recurrence==1)
sts graph, by(race) 
sts test race

********************************** ANNOTATED RESULTS **********************************

 failure _d:  recurrence == 1
   analysis time _t:  recurr_day


Log-rank test for equality of survivor functions

      |   Events         Events
race  |  observed       expected
------+-------------------------
1     |         6           6.60
2     |         5           3.86
3     |         1           1.54
------+-------------------------
Total |        12          12.00

            chi2(2) =       0.61
            Pr>chi2 =     0.7383