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help for survtime                                        (see also:  [R] stset)
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Survival Time for use in stset

        survtime [if exp] [in range] , events(varlist) censors(varlist)
                 [generate(newvarname) sequential origin(varlist) addone]

  NOTE: if generate(newvarname) is not used survtime will create or overwrite
    two variables called event_d: the first occurring date & event_i: the
    corresponding event indicator.

Description

survtime finds the first occurring date of a list of events and censor dates
    and creates one variable event_d (or newvariable_d) for the date and a
    second variable event_i (or newvariable) indicating the status of that date
    as an event (1,2,...) or a censor (0) of types provided in events(varlist)
    and censors(varlist), respectively.

survtime was written with meaningful date (see dates) variables in mind. There
    is no check made for compatible numeric variables specified in
    events(varlist), censors(varlist), or origin(varname).

  stset will use the resulting variable and event indicator. Example syntax of 
    stset following survtime:

        stset event_d [if exp] [in range] [, fail(event_i==numlist)
                origin(varname) scale(#) id(varname)].

Options
           
generate(newvarname) specifies that new variables be created. The date will
    have the suffix _d added. The event indicator will have no suffix added. By
    default event_d and event_i will be created or overwritten.

sequential specifies that the events(varlist) are in descending order of
    interest and values 1,2,... will be so assigned and labeled indicating
    which event occurs first. Tied events will take the preceding event type.
    If sequential is not specified all events(varlist) get the value, 1.

origin(varname) specifies that the number of elapsed days be found from this
    origin. It will contain the number gotten by subtracting the provided
    origin from the event or censor date. The resulting variable will reflect
    this in its label. If this option is used it is not necessary to use the
    origin() option in stset.

addone specifies that one be added to the interval. If this option is specified
    without origin(varname), zero is used as the origin.

[if exp] [in range] options result in missing values for records excluded
    thereby. In general, it is recommend that the analysis set be defined in 
    stset, or by some other means, rather than in survtime. If timevar in stset
    contains missing values stset responds by indicating probable error, which
    can mask substantial information about survival data. This, however, does
    not matter if survtime is used without stset to find observation time for a
    certain subset.

Example

        . survtime , e(die dmarrel) c(dlast cutoff) gen(dfs) seq
        . stset dfs_d, failure(dfs==1/2) origin(begin_d) scale(365)
            id(idnumber)

        . survtime , e(die dmarrel) c(dlast cutoff) gen(dfs)
        . stset dfs_d, failure(dfs==1) origin(begin_d) scale(365) id(idnumber)

Author

        Allen Buxton,
        Assistant Statistician
        Children's Oncology Group
        Arcadia, CA

Also see

 Manual: [R] stset

On-line: help for stset survtime