Thanks Roger for your clarification. Actually, I am interested in
population attributable fractions and as Svend and you suggested, aflogit
is the appropriate command to use in stata.
Mauricio.
VICTOR MAURICIO HERRERA
M.S. Student
Population Health Sciences
University of Wisconsin
610 Walnut St. 632 WARF
Madison, WI 53726
(608) 890-0895
----- Original Message -----
From: "Newson, Roger B" <[email protected]>
Date: Wednesday, April 18, 2007 6:25 am
Subject: RE: st: population attributable risk - confidence intervals
To: [email protected]
> I am not sure whether Mauricio really wanted the population attributable
> risk or the population attributable fraction. Mauricio's formula is what
> I would call the population attributable fraction, equal to the
> population attributable risk as a proportion of the population total
> risk. The atributable risk is a difference between 2 proportions, namely
> the proportion diseased in the existing population and the proportion
> diseased in a hypothetical population with zero exposure. The population
> attributable fraction is the ratio between this difference and the
> proportion diseased in the existing population.
>
> As Svend says, the command
>
> findit population attributable risk
>
> will locate the Stata 5 module -aflogit- (which does not always function
> with Stata 7 and above), and also the official Stata module -epitab-,
> which is up to date, and which also calculates population attributable
> fractions. The formulas used are given in the Stata manual "Survival
> analysis and epidemiological tables", referred to as "[ST]" in the
> on-line help. If Mauricio needs to buy a copy of this manual, then
> Mauricio should refer to
> http://www.stata.com/bookstore/overview.html
> for the Manuals catalog, and refer to
> http://www.stata.com/worldwide/
> to find the nearest distributor for the manuals.
>
> To calculate a confidence interval for the population attributable risk
> (as distinct from the population attributable fraction), use the
> -somersd- package, downloadable from SSC using the -ssc- command in
> Stata. The population attributable risk is a special case of the
> parameter Somers' D, which is described in Newson (2006a) and Newson
> (2006b). If Mauricio (or anybody else) wants to know how to do this,
> then I can give an example.
>
> I hope this helps.
>
> Roger
>
> Newson R. 2006a. Confidence intervals for rank statistics: Somers' D
> and
> extensions. The Stata Journal 6(3): 309-334. Download pre-publication
> draft from
> http://www.imperial.ac.uk/nhli/r.newson/
>
> Newson R. 2006b. On the central role of Somers' D. Presented at the 12th
> UK Stata User Meeting, 11-12 September, 2006. Download from
> http://www.imperial.ac.uk/nhli/r.newson/
>
>
> Roger Newson
> Lecturer in Medical Statistics
> Respiratory Epidemiology and Public Health Group
> National Heart and Lung Institute
> Imperial College London
> Royal Brompton campus
> Room 33, Emmanuel Kaye Building
> 1B Manresa Road
> London SW3 6LR
> UNITED KINGDOM
> Tel: +44 (0)20 7352 8121 ext 3381
> Fax: +44 (0)20 7351 8322
> Email: [email protected]
> www.imperial.ac.uk/nhli/r.newson/
>
> Opinions expressed are those of the author, not of the institution.
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Svend Juul
> Sent: 18 April 2007 08:02
> To: [email protected]
> Subject: Re: st: population attributable risk - confidence intervals
>
>
> Mauricio Herrera wrote:
>
> I wonder if there is a routine to calculate population attributable
> risks and their corresponding 95% confidence intervals using Levine's
> formula: PAR=[Pe*(RR-1)]/[1+ Pe*(RR-1)].
> Pe: prevelance of exposure in the population; RR: relative risk.
> ------------------------------------------------------
>
> Try:
>
> findit population attributable risk
>
> and locate -aflogit-. It claims to do the job.
>
> Hope this helps
>
> Svend
>
> __________________________________________
>
> Svend Juul
> Institut for Folkesundhed, Afdeling for Epidemiologi
> (Institute of Public Health, Department of Epidemiology)
> Vennelyst Boulevard 6
> DK-8000 Aarhus C, Denmark
> Phone: +45 8942 6090
> Home: +45 8693 7796
> Email: [email protected]
> __________________________________________
>
> *
> * For searches and help try:
> * http://www.stata.com/support/faqs/res/findit.html
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/
>
> *
> * For searches and help try:
> * http://www.stata.com/support/faqs/res/findit.html
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/
>
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
