Calucing person-years and incidence rates                         (STB-7: sbe5)
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	^pyears^ dob begin end [dead], ^i(^#_interval^) g(^#_groups^) s(^#_start_age^)
					[ ^l^ist ^d^ead ]

where


      ^dob^ = date of birth elapsed-date variable
    ^begin^ = date of entry into test or trial elapsed-date variable
      ^end^ = date of end of trail, case failure, or out of trial(censored) 
            elapsed-date variable
     ^dead^ = optional variable; must specify dead option as well; coded 1
            (failure) or 0 (censored).
     ^i(#)^ = interval length  ex: ^i(5)^; integer only
     ^g(#)^ = number of age groups  ex: ^g(4)^; integer only
     ^s(#)^ = beginning year of age for first group in study
              ex: ^s(30)^; integer only



Description
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^pyears^ calculates person-years and failures per age group.


Options 
-------

^list^ produces a casewise listing of per-group person-year contribution.

^dead^ requests statistics on number of failures per group (numerator for 
    incidence rates), plus number of entries and completions per age group.


Example
-------

 . ^pyears sdob bs es dead, i(5) g(4) s(30) l d^

where there are 4 groups of 5 years intervals with the beginning age of 
the first group being 30. 


Author
------

Joseph Hilbe, editor, STB.  Fax 602-860-1446.


Also see
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    STB:  sbe5 (STB-7)