st: should I or shouldn"t I use _time0(var)_ for left truncation (delayed entry)?

["josemaria" <jmpsouza@usp.br>]

Dear statalisters:
   the manuals and the help for stset say that _time0 ()_ "is rarely 
specified... and should be used exclusively with multiple-record data, and 
even then it should be considered whether _origin()_ or _enter()_ would be 
more appropriate". However, the book  An Introduction to Survival Analysis 
Using Stata, by Cleves, Gould & Gutierrez, first edition, on pages 92-94, 
shows the use of _time0()_ for left truncation (delayed entry) and not for 
multiple-record data.  Can the _stcox_ command  be used to complete the 
analysis ? I have a data set  with a situation alike  the example (subjets 
enter at several different times to form the risk sets) and I am at lost 
with the options for stset.
   Thank for the help,
Jos� Maria

Jos� Maria Pacheco de Souza, Professor Titular (aposentado)
Departamento de Epidemiologia
Faculdade de Sa�de P�blica/Universidade de S�o Paulo
Av. Dr. Arnaldo, 715 cep 01246-904
S�o Paulo Brasil
fones (11)3082-3886  (11)3061-7724 (11)3714-2403  (11)3768-8612
fax   (11)3082-2920  (11)3714-2403
www.fsp.usp.br/~jmpsouza
jmpsouza@usp.br

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