.-
help for ^clfpois^   95 % Confidence Limits for Rates based on "Poisson" outcome
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Syntax

cflpois Count Denominator [if] [in] [, ^B^y(string) ^N^(string)  ^M^ult(real 100000.0)]

	Where Count      : name of variable giving outcome   
          Denominator: variable containing time at risk

^Description^
----------
 Cflpois Confidence Limitis for poisson distributed outcome (Stata 6)

 Clfpois is relevant for overall and stratified (conditional) tabulation of 
 incidence rates based on two variables count and time at risk.

 This module is almost through testing but ^appropriate caution^ 
 should still be applied until a notice has been given to the stata-list

 By default observations with missing (.) will be excluded from the calculations,
 but not from the stratified table.

 The rate is calculated as: Count/Denominator

Reference:
 Stata ^cii^ routine is used for the actual calculation

example:
 ^cflpois inj  pyrs , by(hrs_wk)^

 hrs_wk      N     inj       pyrs     rate        l  a     h 
  1-13     234     47       54433     86.3     62.9  -  115.7  
 14-35     136     38      151370     25.1     17.9  -  34.1  
   36+     298    178      729396     24.4     21.0  -  28.3  

     t       N    inj        pyrs      rate        l  a    h 
 Total     668    263      935199      28.1     25.0  -  31.9  


^Options^
--------
^B^y        Stratify by this (or these) variables. 
^N^         Indicate number of persons on which the calculations are based.
            Default is that each record counts as one person. The number of persons
            is only used to display the observation counts. 
^M^ult      Multiplier for rates. Default 100.000. That is rates are counts/100000 time units.

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Files are: cflpois.ado, cflpois.hlp

Latest version accessible for download from http://www.bola.suite.dk

Examples
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 . ^cflpois count pyrs
 . ^cflpois count pyrs, by(sex agegrp) N(persons)
 . ^cflpois count pyrs, mult(1000) 
 . ^cflpois count pyrs, by(sex agegrp kohort)

 Applying if in 
 . ^cflpois c1 pyrs if r > 0^ 
 . ^cflpois c1 pyrs in 1/400^, by(v3)

 weights not tested !
 
Author
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         Jens M.Lauritsen, Accident Analysis Group, Odense University Hospital
                           Odense Denmark. jm.lauritsen@@dadlnet.dk
Also see
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On-line: help for @cc@ @ir@  @epitab@




